LI 3.2 User Manual.book

LI 3.2 User Manual.book
Living Image® Software
User’s Manual
Version 3.2
© 2002-2009 Xenogen Corporation. All rights reserved.
PN 125112
Caliper Life Sciences
68 Elm Street
Hopkinton, MA 01748
USA
1.877.522.2447 (US)
1.508.435.9500
Fax: 1.508.435.3439
E-mail: [email protected]
www.caliperls.com
Discovery in the Living Organism, IVIS Imaging System and Living Image are either registered trademarks or
trademarks of Xenogen Corporation. The names of companies and products mentioned herein may be the
trademarks of their respective owners. Apple, Macintosh and QuickTime are registered trademarks of Apple
Computer, Inc. Microsoft, PowerPoint and Windows are either registered trademarks or trademarks of Microsoft
Corporation in the United States and/or other countries. Adobe and Illustrator are either registered trademarks or
trademarks of Adobe Systems Incorporated in the United States and/or other countries.
Living Image® Software User’s Manual
Contents
1 Welcome . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.1 What’s New In the Living Image 3.2 Software . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 About This Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.3 Contacting Caliper Technical Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2 Getting Started . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.1 Overview of Imaging & Image Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.2 Starting the Living Image® Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.3 Initializing the IVIS® Imaging System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.4 Checking the System Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.5 About the IVIS Acquisition Control Panel & Auto Exposure Feature . . . . . . . . . . . . . 12
3 Acquire an Image or Image Sequence . . . . . . . . . . . . . . . . . . . . . . . 15
3.1 Acquire a Bioluminescence Image . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3.2 Acquire a Fluorescence Image With Epi-Illumination . . . . . . . . . . . . . . . . . . . . . 18
3.3 Acquire a Fluorescence Image With Transillumination . . . . . . . . . . . . . . . . . . . . . 19
3.4 Acquire an Image Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
3.5 Manually Setting the Focus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
3.6 Manually Saving Image Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
3.7 Exporting Image Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
4 Acquire Kinetic Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
4.1 Kinetic Acquisition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
4.2 Viewing & Editing Data (Kinetic Acquisition window) . . . . . . . . . . . . . . . . . . . . . 42
4.3 Saving Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
5 Working With Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
5.1 Browsing & Opening Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
5.2 The Tool Palette & Image Window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
5.3 Working With an Image Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
5.4 Working With a Single Image . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
5.5 Viewing Image Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
5.6 Image Layout Window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
5.7 Adjusting Image Appearance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
5.8 Correcting or Filtering Image Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
5.9 Image Information Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
5.10 Rendering Intensity Data in Color . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
5.11 Viewing Transillumination Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
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Contents
5.12 Viewing & Editing Kinetic Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
6 Working With ROI Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
6.1 About ROIs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
6.2 ROI Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
6.3 Measuring ROIs in an Image . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
6.4 Measuring Background-Corrected Signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
6.5 Measuring ROIs in Kinetic Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
6.6 Managing ROIs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
6.7 Managing the ROI Measurements Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
7 Image Math . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
7.1 Using Image Math to Create a New Image . . . . . . . . . . . . . . . . . . . . . . . . . . 112
7.2 Subtracting Tissue Autofluorescence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
7.3 Overlaying Multiple Images . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118
8 Planar Spectral Image Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . 121
8.1 Planar Spectral Image Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
8.2 Planar Spectral Imaging Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
8.3 Viewing & Exporting Graphical Results . . . . . . . . . . . . . . . . . . . . . . . . . . . 125
8.4 Managing Planar Spectral Imaging Results . . . . . . . . . . . . . . . . . . . . . . . . . . 126
9 Spectral Unmixing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
9.1 Spectral Unmixing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128
9.2 Spectral Unmixing Results Window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
9.3 Spectral Unmixing Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132
9.4 Spectral Unmixing Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134
10 Generating a Surface Topography . . . . . . . . . . . . . . . . . . . . . . . . 139
10.1 Generate the Surface Topography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
10.2 Managing Surfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142
11 Point Source Fitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143
11.1 Displaying the Point Source Fitting Tools . . . . . . . . . . . . . . . . . . . . . . . . . . 143
11.2 Point Source Fitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
11.3 Checking the Point Source Fitting Results . . . . . . . . . . . . . . . . . . . . . . . . . . 148
11.4 Exporting Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148
11.5 Managing Point Source Fitting Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149
12 3D Reconstruction of Sources . . . . . . . . . . . . . . . . . . . . . . . . . . 151
12.1 3D Reconstruction of Bioluminescent Sources . . . . . . . . . . . . . . . . . . . . . . . . . 152
12.2 3D Reconstruction of Fluorescent Sources . . . . . . . . . . . . . . . . . . . . . . . . . . 156
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Living Image® Software User’s Manual
12.3 DLIT & FLIT Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158
12.4 3D Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164
12.5 3D Tools - Mesh Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170
12.6 3D Tools - Volume Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172
12.7 3D Tools - Organs Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175
12.8 3D Tools - Animation Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182
12.9 Managing DLIT/FLIT Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187
13 Troubleshooting Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189
13.1 DLIT/FLIT Analysis Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189
Appendix A IVIS Acquisition Control Panel . . . . . . . . . . . . . . . . . . . . . 191
Appendix B Preferences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195
B.1 General Preferences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196
B.2 User Preferences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198
B.3 Acquisition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199
B.4 Theme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200
B.5 Tissue Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201
B.6 3D Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202
Appendix C Detection Sensitivity . . . . . . . . . . . . . . . . . . . . . . . . . . 205
C.1 CCD Detection Efficiency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205
C.2 Binning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206
C.3 Smoothing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208
Appendix D Image Data Display & Measurement . . . . . . . . . . . . . . . . . . 211
D.1 Image Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211
D.2 Quantifying Image Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213
D.3 Flat Fielding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216
D.4 Cosmic Ray Corrections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216
Appendix E Luminescent Background Sources & Corrections . . . . . . . . . . 217
E.1 Electronic Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217
E.2 Background Light On the Sample . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 218
E.3 Background Light From the Sample . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220
Appendix F Fluorescent Imaging . . . . . . . . . . . . . . . . . . . . . . . . . . 223
F.1 Description and Theory of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223
F.2 Filter Spectra . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225
F.3 Working with Fluorescent Samples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 227
F.4 Image Data Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 228
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Contents
F.5 Fluorescent Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 229
F.6 Subtracting Instrument Fluorescent Background . . . . . . . . . . . . . . . . . . . . . . . 235
F.7 Adaptive Background Subtraction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 235
F.8 Subtracting Tissue Autofluorescence Using Background Filters . . . . . . . . . . . . . . . 236
Appendix G Planar Spectral Imaging . . . . . . . . . . . . . . . . . . . . . . . . 239
G.1 Planar Spectral Imaging Theory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239
G.2 Optical Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241
G.3 Luciferase Spectrum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241
G.4 An Example of Planar Spectral Imaging . . . . . . . . . . . . . . . . . . . . . . . . . . . 241
G.5 Optimizing the Precision of Planar Spectral Analysis . . . . . . . . . . . . . . . . . . . . . . 245
Appendix H 3D Reconstruction of Light Sources . . . . . . . . . . . . . . . . . . 247
H.1 Determining Surface Topography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247
H.2 Algorithm Parameters & Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 252
Appendix I IVIS® Syringe Injection System . . . . . . . . . . . . . . . . . . . . . 257
I.1 Controlling the Infusion Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257
I.2 Tracking Infusion in the Maximum vs. Time Graph . . . . . . . . . . . . . . . . . . . . . . . 259
I.3 Closing the Infusion Pump Control Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . 259
Appendix J Menu Commands, Tool Bar, & Shortcuts
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. . . . . . . . . . . . . . . 261
Living Image® Software User’s Manual
1 Welcome
What’s New In the Living Image 3.2 Software . . . . . . . . . . . . . . . . . . . . . . . . 1
About This Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Contacting Caliper Technical Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
The Living Image® 3.2 software controls image acquisition on the IVIS® Kinetic. The
application also provides tools for optimizing image display and analyzing images or
kinetic data.
1.1 What’s New In the Living Image 3.2 Software
The Living Image 3.2 software enables kinetic data acquisition on the IVIS® Kinetic and
provides tools for visualizing and analyzing kinetic data.
New Feature or Updated Tool
See Page
Acquire and analyze luminescent or fluorescent signals in real-time
37
14-bit or 16-bit dynamic range
39
EM gain option multiplies the signal for fast imaging applications
40
Maximum signal vs. time graph plots the maximum signal in each frame of the
kinetic data and provides a convenient way to see signal trends
41
View the cumulative signal to track signal changes in real time
40
Kinetic ROIs are applied to each frame in a kinetic data set and are displayed during
kinetic data playback
94
Edit kinetic data
42
Save kinetic data in DICOM format (.dcm) or save kinetic images to a movie (for
example, .mpg4)
43
1.2 About This Manual
This user manual explains how to acquire and analyze images or kinetic data on the
IVIS® Kinetic. The manual provides detailed instructions and screenshots that depict the
system response.
NOTE
Sometimes the screenshots in the manual may not exactly match those displayed on
your screen.
For more details on the IVIS Kinetic, please see the appropriate IVIS Kinetic System
Manual.
1
1. Welcome
Conventions Used In
the Manual
Convention
Example
Menu commands are bolded.
To open image data, select File ➞Open Dataset on the
main bar.
Toolbar button names are bolded.
To open image data, click the Open Dataset button
.
Numbered steps explain how to carry
out a procedure.
1. To start the Living Image software, click the
icon on the desktop.
A dash (—) precedes the description
of the system response to a
procedure.
Document names are italicized.
Note information
— The main window appears.
Living Image Software User’s Guide
NOTE
A note presents pertinent details on a topic.
or
Note: Notes also appear in this format.
Caution information
!
CAUTION
CAUTION! A caution note warns you that your
actions may have nonreversible consequences
or may cause loss of data.
Important information
!
IMPORTANT
ALERT! Important information advises you of
actions that are essential to the correct
performance of the instrument or software.
Living Image Help
There are several ways to obtain help on the software features:
• To view a tooltip about a button function, put the mouse cursor over the button.
• To view a brief description about an item in the user interface, click the toolbar
button, then click the item.
• Press F1 or select Help →User Guide on the menu bar to display the Living Image
3.2 Software User’s Manual (.pdf).
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Living Image® Software User’s Manual
1.3 Contacting Caliper Technical Support
If you need technical support, please contact Caliper at:
Telephone:
1.877.LabChip (877.522.2447) Toll Free in the United States)
1.508.435.9761
E-mail:
[email protected]
Fax:
1.508.435.0950
Address:
Caliper Life Sciences
68 Elm Street
Hopkinton, MA 01748
USA
3
1. Welcome
[This page intentionally blank.]
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Living Image® Software User’s Manual
2 Getting Started
Overview of Imaging & Image Analysis . . . . . . . . . . . . . . . . . . . . . .
For more details on sequence setup using the imaging wizard, see page 24.
Initializing the IVIS® Imaging System . . . . . . . . . . . . . . . . . . . . . . .
Checking the System Temperature . . . . . . . . . . . . . . . . . . . . . . . .
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This chapter provides a brief overview of images and image analysis. It also explains
how to start the Living Image® software and initialize the IVIS® imaging system.
2.1 Overview of Imaging & Image Analysis
For bioluminescence imaging, the imaging system acquires a photographic image and a
bioluminescence image. The Living Image software automatically coregisters the
images to generate an overlay image (Figure 2.1). For fluorescence imaging, the IVIS®
imaging system acquires a photographic and fluorescence image that are used to
generate an overlay image.
Table 2.1 Images used to generate an overlay image
Image Type
Description
Photographic
A short exposure of the subject illuminated by the lights located at the top
of the imaging chamber (Figure 2.2). The photographic image is displayed
as a grayscale image.
Bioluminescence
A longer exposure of the subject taken in darkness to capture low level
bioluminescence emission. The bioluminescence image is displayed in
pseudocolor that represents intensity (Figure 2.1). For more details on
bioluminescence image data, see Appendix D, page 211.
Fluorescence
An exposure of the subject illuminated by filtered light. The target
fluorophore emission is captured and focused on the CCD camera.
Fluorescence image data can be displayed in units of counts or photons
(absolute, calibrated), or in terms of efficiency (calibrated, normalized). For
more details on fluorescence image data, see Appendix F, page 223
Figure 2.3
shows an example workflow on an IVIS® Imaging System.
5
2. Getting Started
Photographic image
Bioluminescent image
Overlay image
Figure 2.1 Example bioluminescence overlay image
The Living Image® software automatically coregisters the photographic and bioluminescence
images to generate the overlay image.
Illumination LEDs
Camera lens opening
Sample stage
Figure 2.2 IVIS® Imaging System 100 Series, interior view.
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Living Image® Software User’s Manual
➊ Start the Living Image® software. In the control panel
that appears, initialize the IVIS® imaging system.
➋ Confirm the default user preferences or specify
new preferences.
➌ Specify acquisition settings for a single image, image
sequence, or kinetic sequence.
➍ Acquire the image(s) or kinetic sequence.
Tool
palette
➏ View the image(s) or kinetic data. Analyze an image (Table 2.2), image sequence (Table 2.3), or kinetic data
Figure 2.3 Example imaging and analysis workflow
7
2. Getting Started
Table 2.2 Image or kinetic sequence analysis tools
Tool Palette
Use The Tools to...
See Page
Image Adjust
• Tune the photograph brightness, gamma (similar to contrast), or opacity
• Set the image display color scale min and max
• Select a color table for image display
62
Corrections/Filtering
•
•
•
•
Subtract dark background from the image data
Apply flat field correction to the image data
Specify pixel binning
Smooth the pixel signal
66
Image Information
•
•
•
•
Display x,y coordinates and intensity data at a user-selected location on the image
Display a histogram of pixel intensities in an image
Plot the intensity (y-axis) at each pixel (x-axis) along a user-specified line in the image
Measure distance in an image
67
ROI
• Measure counts or photons in a user-specified region of interest (ROI) and compute
measurement statistics (for example, average, min, max, standard deviation)
• Measure efficiency in the ROI and compute measurement statistics (for fluorescent
images only)
81
Table 2.3 Analyzing image sequences
Analysis
Description
Wizard
Available
See Page
Planar Spectral Image
Analysis
Determines the average depth and total photon flux of a bioluminescent
point source in a user-specified region of interest. Analyzes a sequence of
bioluminescent images acquired using different emission filters.
Yes
121
Image Math
A method for mathematically combining two images (add, multiply, or
subtract). Use image math to:
No
118
• Remove autofluorescence from a fluorescent image
• Display multiple bioluminescent or fluorescent images on the same
photographic image so that you can view multiple reporters in one image
Spectral Unmixing
Removes tissue autofluorescence from a fluorescence image. Analyzes a
sequence of fluorescence images acquired using the fluorophore
excitation filter and several different emission filters. Spectral unmixing can
be applied to images acquired using epi-illumination (excitation light above
the stage) or transillumination (excitation light below the stage).
Yes
121
Point Source Fitting
Estimates the optical properties of tissue, the location and power of a point
source, or the fluorescent yield of fluorophores.
Yes
143
3D Fluorescence
Imaging Tomography
(FLIT™)
A 3-dimensional reconstruction of the image (tomographic analysis) that
estimates the location and intensity of a fluorescent light-emitting source.
Analyzes a sequence of fluorescent images acquired on the IVIS Spectrum
at different transillumination points (excitation light below the stage).
Yes
152
3D Diffuse
Luminescence
Tomography (DLIT™)
A 3-dimensional reconstruction of the subject (tomographic analysis) that
estimates the depth and intensity of a bioluminescent light-emitting
source.
Yes
156
NOTE
For more details on sequence setup using the imaging wizard, see page 24.
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Living Image® Software User’s Manual
2.2 Starting the Living Image® Software
For information on installing the software, see the Installation Guide included on the
Living Image CD ROM. By default, the software is installed at:
PC: C:Programs:Xenogen:Living Image 3.2
Macintosh: Applications:Xenogen:LivingImage 3.2
NOTE
All components of the IVIS® Imaging System should be left on at all times due to the
long cooling time required to reach operating (demand) temperature. It is also
important to leave the system on to enable automatic overnight electronic background
measurements. Periodically rebooting the computer is permissible and does not affect
the camera operation.
To start the software:
1. PC Users: Click the Windows Start menu button
and select All Programs →
Living Image. Alternatively, click the Living Image® software desktop icon .
Macintosh Users: Click the Living Image software desktop icon
software from the application folder.
or run the
- The main window appears.
2. Select a user ID from the dropdown list or enter a new User ID
(up to three letters), and click OK.
- The control panel appears if the
workstation controls the IVIS
Imaging System (see next page).
9
2. Getting Started
Menu bar (for more details, see Appendix J, page 261)
Toolbar
The acquisition control panel when the workstation controls the IVIS® Imaging
System (for more details, see Appendix A, page 191).
NOTE
The Living Image® software on the PC workstation that controls the IVIS® Imaging
System includes both the acquisition and analysis features. The Living Image software
on other workstations includes only the analysis features. Macintosh users have
access to only the analysis features of the Living Image software.
There are several ways to obtain help on the software features:
• To view a tooltip about a button function, put the mouse cursor over the button.
• To view a brief description about an item in the user interface, click the toolbar
button, then click the item.
Press F1 or select Help →User Guide on the menu bar to display the Living Image 3.2
Software User’s Manual (.pdf).
10
Living Image® Software User’s Manual
2.3 Initializing the IVIS® Imaging System
The imaging system must be initialized each time the Living Image® software is started,
or if the power has been cycled to the imaging chamber or the camera controller (a
component of some IVIS systems). The initialization procedure moves every motordriven component in the system (for example, stage and lens) to a home position, resets
all electronics and controllers, and restores all software variables to the default settings.
Initialization may be useful in error situations. For further details on instrument
operation, see the hardware manual for your IVIS Imaging System.
To initialize the imaging system:
1. Start the Living Image software (double-click the
icon on the desktop).
2. In the control panel that appears, click Initialize.
- You will hear the motors move.
NOTE
The control panel is only available on the workstation that controls the imaging
system. The items available in the IVIS® System control panel depend on the
particular IVIS Imaging System and the imaging mode selected (luminescent or
fluorescent, Image Setup or Sequence Setup mode).
2.4 Checking the System Temperature
The temperature box in the IVIS acquisition control panel indicates the temperature
status of the charge coupled device (CCD) camera (Figure 2.4). After you initialize the
system, the temperature box turns green when the temperature is locked at the demand
temperature (-90° C or -105° C for IVIS Systems cooled by a Cryotiger® unit),
indicating the instrument is ready for operation and image acquisition.
The demand temperature for the CCD camera is fixed. Electronic feedback control
maintains the CCD camera temperature to within a few degrees of the demand
temperature.
The default stage temperature on the IVIS® imaging system is 37° C, but may be set to
a temperature from 25-40° C.
11
2. Getting Started
Click the temperature box to
view the demand and
measured temperatures of
the CCD camera and stage.
Temperature box color indicates:
System not initialized.
System is initialized, but CCD camera
temperature is out of range.
System is initialized and CCD camera is at or
within acceptable range of the demand
temperature and locked. The system is ready
for imaging.
Figure 2.4 IVIS® acquisition control panel
NOTE
The items in the IVIS System control panel depend on the particular IVIS Imaging
System and the imaging mode selected (luminescent or fluorescent, Image Setup or
Sequence Setup mode). For more details on the control panel, see Appendix A,
page 191.
The IVIS® Imaging System is ready for image acquisition after the system is initialized
and the operating (demand) temperature of the CCD camera is reached (locked). The
Living Image® software on the PC workstation that controls the IVIS Imaging System
includes both the acquisition and analysis features. The Living Image software on other
workstations includes only the analysis features.
2.5 About the IVIS Acquisition Control Panel & Auto Exposure Feature
The control panel (Figure 2.5) provides the image acquisition functions. For details on
the imaging parameters in the control panel, see Appendix A, page 191.
The auto exposure setting is useful in situations where the signal strength is unknown
or varies widely, for example during a time course study. When you choose auto
exposure (Figure 2.5), the system acquires an image at maximum sensitivity, then
calculates the required settings to achieve, as closely as possible, an image with a userspecified target max count. If the resulting image has too little signal or saturated
pixels, the software adjusts the parameters and takes another image.
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Living Image® Software User’s Manual
In most cases, the default auto exposure settings provide a good bioluminescence or
fluorescence image. However, you can modify the auto exposure preferences to meet
your needs. For more details, see page 199.
To acquire an image using auto exposure,
click the
arrow and select Auto.
Luminescence
imaging settings
Fluorescence
imaging settings
Photographic
imaging settings
Structured light
imaging settings
Figure 2.5 IVIS acquisition control panel, auto exposure selected
NOTE
The options available in the IVIS acquisition control panel depend on the selected
imaging mode, the imaging system, and the filter wheel or lens option that are
installed.
13
2. Getting Started
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Living Image® Software User’s Manual
3
Acquire an Image or Image Sequence
Acquire a Bioluminescence Image . . . . . . . . . . . .
Acquire a Fluorescence Image With Epi-Illumination .
Acquire a Fluorescence Image With Transillumination
Acquire an Image Sequence . . . . . . . . . . . . . . .
Manually Setting the Focus . . . . . . . . . . . . . . . .
Manually Saving Image Data . . . . . . . . . . . . . . .
Exporting Image Data . . . . . . . . . . . . . . . . . . .
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. 34
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. 35
The IVIS® Imaging System is ready for image acquisition after the system is initialized
and the CCD camera reaches operating (demand) temperature (locked).
3.1 Acquire a Bioluminescence Image
1. Start the Living Image software (double-click the
icon on the desktop).
2. Initialize the IVIS System and confirm or wait for the CCD temperature to lock. (For
more details, see page 11.)
3. Put a check mark next to Luminescent.
4. Confirm that Excitation Filter setting is Block and the Emission Filter setting is
Open.
5. Select the Auto exposure time (click the
arrow). Alternately, manually set the
exposure, binning, and F/Stop. (For more details on the control panel settings, see
page 191.)
6. Set the field of view: Make a selection from the Field of View drop-down list. For
more details on the field of view, see page 160.
15
3. Acquire an Image or Image Sequence
NOTE
To view the subject(s) inside the chamber before image acquisition, take a
photographic image (uncheck the luminescent or fluorescent option, choose the
Photographic and Auto options, and click Acquire).
7. Set the focus:
• Select use subject height from the Focus drop-down list and use the arrows
or the keyboard arrows to specify a subject height (cm).
or
• Select Manual focus from the Focus drop-down list. (For more details on manual
focusing see page 34.)
8. Set the photographic image settings:
a. Choose the Photographic option.
b. Enter an exposure time or choose the Auto option.
c. Confirm the binning and f/stop defaults or specify new settings for the photographic
image.
9. If necessary, click
in the control panel to operate in single image mode.
NOTE
In single image mode, the
button appears in the control panel. Click this
button to set up sequence acquisition. (For more details on setting up a sequence,
see page 22.)
10. When you are ready to acquire the image, click Acquire. During image acquisition,
the Acquire button becomes a Stop button. To cancel the acquisition, click Stop.
- The image window appears (Figure 3.1). If this is the first image of the session,
you are prompted to choose an autosave location.
11. To specify a folder for autosaved data, click Yes in the prompt and choose a folder
in the dialog box that appears.
- All images acquired during the session are automatically saved to this folder. You
can choose a different folder at any time (select Acquisition →Auto-Save on the
menu bar).
12. In the Edit Image Labels box that appears, enter information for the image label and
click OK (Figure 3.1). If you do not want to enter label information, click Cancel.
16
Living Image® Software User’s Manual
Image
label
Tool
palette
Color bar
In the color bar, check the image min and max to determine whether the signal of
interest is above the noise level and below CCD saturation. For 16 bit imaging, a
signal ranging from ~600 - 60,000 counts is recommended; for 14-bit imaging,
~600-16,000 counts are recommended. If the signal level is unacceptable, adjust
the exposure time or binning level. For more details on the image window, see
Table 3.1, page 18.
Edit the label information here.
Edit Image Labels box
Figure 3.1 Image window & Edit Image Labels box
17
3. Acquire an Image or Image Sequence
Table 3.1 Image window
Item
Description
Units
Select the measurement units for the image display (counts, photons, or
efficiency) from this drop-down list
Display
Select the image type (for example, overlay) that you want to display from this
drop-down list. For more details on the different types of image displays, see
Figure 5.6, page 57.
Info
Click to display or hide the image label information.
Opens a dialog box that enables you to export the active view as a graphic file.
Color bar
Shows the minimum and maximum pixel intensities in the image as well as the
color bar. Pixels less than the color bar minimum or greater than the color bar
maximum are not displayed in the image.
Image label
Information about the image that the software automatically records and userspecified information entered in the Edit Image Label dialog box.
3.2 Acquire a Fluorescence Image With Epi-Illumination
Epi-illumination uses an excitation light source located above the stage. For more
details on fluorescence imaging, see page 169.
1. Start the Living Image software (double-click the
icon on the desktop).
2. Initialize the IVIS System and confirm or wait for the CCD temperature to lock. (For
more details, see page 11.)
3. Put a check mark next to Fluorescent.
4. Confirm that the Fluorescent Lamp Level is set to the appropriate level (High or
Low).
5. Select the Auto exposure time (click the
arrow). Alternately, manually set the
exposure, binning, and F/Stop. (For more details on the control panel settings, see
page 191.)
6. Set the FOV: To adjust the field of view (FOV), make a selection from the Field of
View drop-down list. For more details on FOV, see page 160.
18
Living Image® Software User’s Manual
NOTE
To view the subject(s) inside the chamber before image acquisition, take a
photographic image (clear the luminescent or fluorescent option, choose the
Photographic and Auto options, and click Acquire).
7. Set the focus:
• Select use subject height from the Focus drop-down list and use the arrows or
the keyboard arrows to specify a subject height (cm).
or
• Select Manual focus from the Focus drop-down list. (For more details on manual
focusing see page 34.)
8. If necessary, click
in the control panel to operate in single image mode.
NOTE
In single image mode, the
button appears in the control panel. Click this
button to set up sequence acquisition. (For more details on setting up a sequence, see
page 22.)
9. When you are ready to acquire the image, click Acquire. During image acquisition,
the Acquire button becomes a Stop button. To cancel the acquisition, click Stop.
- The image window appears (Figure 3.1). If this is the first image of the session, you
are prompted to choose an autosave location.
10. To specify a folder for autosaved data, click Yes in the prompt and choose a folder
in the dialog box that appears.
- All images acquired during the session are automatically saved to this folder. You
can choose a different folder at any time (select Acquisition →Auto-Save on the
menu bar).
11. In the Edit Image Labels box that appears, enter information for the image label and
click OK (Figure 3.1). If you do not want to enter label information, click Cancel.
3.3 Acquire a Fluorescence Image With Transillumination
Transillumination uses an excitation light source located below the stage. For more
details on fluorescence imaging, see page 169.
NOTE
Transillumination is only available on the IVIS® Spectrum imaging system.
19
3. Acquire an Image or Image Sequence
1. Start the Living Image software (double-click the
icon on the desktop).
2. Initialize the IVIS System and confirm or wait for the CCD temperature to lock. (For
more details, see page 11.)
3. Put a check mark next to Fluorescent and Transillumination.
4. In the control panel, select an appropriate excitation filter and emission filter from
the drop-down lists.
5. Click Setup.
6. In the Transillumination Setup box
that appears, choose the locations for
transillumination and image
acquisition and click OK.
For more details on the
Transillumination Setup box, see
Table 3.2.
20
Living Image® Software User’s Manual
Table 3.2 Transillumination Setup box
Item
Description
Move Motors To
Selected Spot
Transillumination motors will move to the grid location selected in the
Transillumination Setup dialog box.
Transillumination
Lamp Source
Choose this option to turn on the bottom illumination lamp.
Mask Grid points
To Subject
Choose this option to select only the grid locations within the subject.
Grid locations outside the subject are masked.
Grid Type
Select a grid type from the drop-down list: 15x23, 11x23, 5x10, or 8x12
well plate, Xenogen Sparse Mask, 6x8x1cm.
Grid Display
Select "Points" or "Cross Hair" to display the grid.
Update Photograph Click to acquire a new photographic image. If the chamber door is opened
during transillumination setup, you are prompted to acquire a new
photograph.
Clear Selections
Clears selected/ highlighted transillumination locations on the grid.
7. Set the FOV: To adjust the field of view (FOV), make a selection from the Field of
View drop-down list. For more details on FOV, see page 160.
NOTE
To view the subject(s) inside the chamber before image acquisition, take a
photographic image (clear the luminescent or fluorescent option, choose the
Photographic and Auto options, and click Acquire).
8. Set the focus:
• Select use subject height from the Focus drop-down list and use the arrows or
the keyboard arrows to specify a subject height (cm).
or
• Select Manual focus from the Focus drop-down list. (For more details on manual
focusing see page 34.)
9. If necessary, click
in the control panel to operate in single image mode.
NOTE
In single image mode, the
button appears in the control panel. Click this
button to set up sequence acquisition. (For more details on setting up a sequence, see
page 22.)
10. When you are ready to acquire the image, click Acquire. During image acquisition,
the Acquire button becomes a Stop button. To cancel the acquisition, click Stop.
- The image window appears (Figure 3.1). If this is the first image of the session, you
are prompted to choose an autosave location.
21
3. Acquire an Image or Image Sequence
11. To specify a folder for autosaved data, click Yes in the prompt and choose a folder
in the dialog box that appears.
- All images acquired during the session are automatically saved to this folder. You
can choose a different folder at any time (select Acquisition →Auto-Save on the
menu bar).
12. In the Edit Image Labels box that appears, enter information for the image label and
click OK (Figure 3.1). If you do not want to enter label information, click Cancel.
3.4 Acquire an Image Sequence
A sequence is a collection of images that are grouped together in a single folder. A
sequence may include images that were acquired during the same session and were
intended to be grouped together (for example, images taken at different exposure times
or an image sequence for DLIT™ or FLIT™ 3-D tomographic analysis).
Images that were acquired during different sessions can also be grouped together to
form a sequence. For example, a time series could be constructed from images acquired
on different days following an experimental treatment. (For more details, see page 26.)
Some analyses are performed on an image sequence (see Table 3.3). The sequence
requirements (number and type of images) depend on the analysis. The imaging wizard
provides a convenient way to set up several types of image sequences (see page 24).
You can also set up the sequence manually (see page 26).
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Living Image® Software User’s Manual
Table 3.3 Application-specific image sequences
Analysis
Planar spectral image analysis
IVIS Imaging System
Lumina
100 Series
200 Series
Spectrum
Kinetic
Optional*
Optional*
T
T
Optional*
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
Optional*
T
T
T
T
T
Computes the total flux and average depth of a
bioluminescent source below the surface.
Display multiple fluorescent or bioluminescent
reporters.
Uses the Image Overlay function to display multiple
luminescent or fluorescent images on one photographic
image.
Subtract tissue autofluorescence using blue-shifted
background filters.
Uses the image math feature to subtract a background
image from the primary image.
Point Source Fitting
Estimates the optical properties of tissue, the location and
power of a point source, or the fluorescent yield of
fluorophores.
Spectral unmixing
Optional*
Optional*
Removes tissue autofluorescence from a fluorescence
image.
DLIT™ Analysis
Reconstructs the surface topography of the subject and the
brightness and 3D location of bioluminescent sources.
FLIT™ Analysis
Reconstructs the surface topography of the subject and
brightness and 3D location of fluorescent sources.
*Optional: with premium filters
23
3. Acquire an Image or Image Sequence
Setting Up a Sequence
Using the Imaging
Wizard
The imaging wizard can automatically setup an image sequence for some applications
that analyze an image sequence (Table 3.3). The wizard guides you through a series of
steps, prompting you for the information that the software requires to set up the image
sequence.
Table 3.4 Imaging wizard sequence options
Bioluminescence
Acquires...
Image
Open Filter
Description
Sequence
T
Acquires an image at maximum sensitivity.
Planar Spectral
T
Analyze the sequence to compute the average depth and total
photon flux of a bioluminescent point source in a region of interest
(ROI).
121
Spectral
Unmixing
T
Analyze the sequence to determine spectral signature of different
reporters in the same image and calculate the contribution of each
reporter on each pixel in the image.
127
DLIT
T
Apply the DLIT™ algorithm to the sequence to reconstruct the 3D
surface topography of the subject and the position, geometry, and
strength of the luminescent sources.
151
Fluorescence
Description
T
See
Page
T
Use the data to make fluorescence measurements.
Filter Scan
T
Helps you determine the optimum excitation and emission filter for
a probe.
Spectral
Unmixing
T
Analyze the sequence to extract the signal of one or more
fluorophores from the tissue autofluorescence.
127
FLIT
T
Apply the FLIT™ algorithm to the sequence to reconstruct the 3D
surface topography of the subject and the position, geometry, and
strength of the fluorescent sources.
156
2D
24
See
Page
Living Image® Software User’s Manual
To set up a sequence using the imaging wizard:
1. Click Sequence Setup in the IVIS acquisition control panel.
- The Sequence Editor appears.
Sequence Editor
4. If necessary, click
and select All to clear the Sequence Editor.
5. Click Imaging Wizard.
Sequence Editor
To begin setting up a bioluminescence
image sequence, click here.
To begin setting up a fluorescence
image sequence, click here.
6. Click Next.
25
3. Acquire an Image or Image Sequence
7. Double-click the type of bioluminescence or fluorescence sequence that you want
to acquire and step through the rest of the imaging wizard.
- The sequence setup appears in the Sequence Editor.
Imaging wizard - Bioluminescence
Imaging wizard - Fluorescence
NOTE
The imaging options available in the imaging wizard depend on the IVIS imaging
system and the installed filter set.
Manually Setting Up a
Sequence
You can manually set up an image sequence in the control panel and save the
information to a Xenogen Sequence Setup file (.xsq).
NOTE
To create an image sequence, it may be convenient to edit a sequence setup
generated by the imaging wizard or an existing sequence setup (.xsq). Save the
revised sequence setup to a new name.
1. Click Sequence Setup in the control panel.
26
Living Image® Software User’s Manual
Sequence Editor
2. If it is necessary to clear the sequence editor that appears, click
All.
and select
3. In the control panel, specify the settings for the first bioluminescence or
fluorescence image in the sequence and the photographic image. (For details on the
imaging parameters in the control panel, see page 191.)
Reuse option
NOTE
If you choose the photograph Reuse option in the control panel, the IVIS® System
acquires only one photographic image for the entire sequence. If this option is not
chosen, the system acquires a photographic image for each image in the sequence.
4. Click
.
- The acquisition parameters are added to the table.
27
3. Acquire an Image or Image Sequence
Click to include the parameter settings
for the photographic image in the editor.
Each row in the editor specifies the acquisition
parameters for one image in the sequence
The image(s) in the sequence editor comprise one segment. You can acquire multiple
segments with a user-specified time delay between acquisitions. This is useful for
acquiring data for kinetic analysis.
5. Repeat step 3 to step 4 for each image in the sequence.
6. To specify a time delay between each acquisition, enter a time in the Delay (min)
box in the Sequence Editor.
7. If you want to save the sequence setup information (.xsq):
a. In the sequence editor, click the Save button
.
b. In the dialog box that appears, select a directory for the file, enter a file name, and click
Save.
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Living Image® Software User’s Manual
Editing an Image
Sequence
You can edit a parameter value, as well as add or remove images from the sequence. A
shortcut menu of edit commands is available when you right-click the Sequence Editor.
Changing an Imaging Parameter
1. In the sequence editor, double-click the cell that you want to edit.
Control panel
Sequence editor
For details on these functions, see Table 3.5.
2. Enter a new value in the cell or make a selection from the drop-down list.
3. To apply the new value to all of the cells in the same column, click
.
4. Click outside the cell to lose focus.
Editing a parameter using the control panel
1. In the sequence editor, select the row that you want to modify.
2. In the control panel, choose new parameter values and/or imaging mode.
3. Click
.
Table 3.5 Sequence Editor
Item
Description
Starts the imaging wizard.
Displays a dialog box that enables you to select and open a sequence
setup (.xsq), sequenceinfo.txt, or clickinfo.txt file.
Displays a dialog box that enables you to save a sequence setup (.xsq).
Display Photographic
Settings
Choose this option to include the photograph exposure time, binning,
and F/Stop in the sequence editor.
Number of Segments Choose this option to set the number of segments to acquire and the
time delay between segments. One segment = the sequence
specified in the sequence editor.
Delay
Specifies a time delay between each segment acquisition.
Applies the selected cell value to all cells in the same column.
Deletes the selected row from the sequence editor.
Updates the selected row in the sequence editor with the acquisition
parameters in the control panel.
29
3. Acquire an Image or Image Sequence
Table 3.5 Sequence Editor
Item
Description
Inserts a row above the currently selected row using the information
from the control panel.
Adds a new row below the currently selected row using information
from the control panel.
Adding or Deleting Images From a Sequence
1. Select the row(s) of interest and right-click the sequence editor to view a shortcut
menu of edit commands (see Table 3.6).
Table 3.6 Sequence editor, shortcut menu edit commands
Command
Description
Copy row(s)
Copies the selected row(s) to the system clipboard.
Select All
Selects all rows in the sequence editor.
Delete row(s)
Deletes the selected row(s) from the sequence editor.
Replace Row(s)
Replaces the row(s) selected in the sequence editor with the rows in the
system clipboard.
Note: The Replace function is only available when the number of rows in
the system clipboard is the same as the number of rows selected in the
sequence editor.
Paste Row(s)
Adds copied rows to end of the sequence.
Alternate method to add a row:
1. In the sequence editor, select the row next to where you want to insert the image.
2. Set the imaging mode and parameters in the control panel.
3. To insert the new image above the selected row, click
new image below the selected row, click
.
30
. To insert the
Living Image® Software User’s Manual
Alternate method to delete one or more rows:
1. Select the row(s) that you want to delete.
2. Click
and choose Selected from the drop-down list.
To clear the sequence editor:
1. Click
.
2. Choose All from the drop-down list.
Acquire the Image
Sequence
The system is ready to acquire the image sequence after you set up the image sequence
in the sequence editor.
1. Initialize the IVIS® System and confirm or wait for the CCD temperature to lock. (For
more details, see page 11.)
2. When you are ready to acquire the images, click Acquire Sequence in the control
panel.
- Thumbnail images appear as the images are acquired. During acquisition, the
Acquire Sequence button becomes a Stop button. To cancel the acquisition, click
Stop.
Tool palette
Thumbnail images
31
3. Acquire an Image or Image Sequence
3.If this is the first acquisition of
the session, you are prompted to
choose an autosave location.
4. To specify a folder for autosaved data, click Yes in the prompt and choose a folder
in the dialog box that appears.
- All sequences acquired during the session are automatically saved to this folder.
You can choose a different folder at any time (select Acquisition →Auto-Save
on the menu bar).
5. In the Edit Image Labels box that appears, enter information for the image label and
click OK (Figure 3.1). If you do not want to enter label information, click Cancel.
Image label
Open an image (double-click the thumbnail) to
determine whether the signal of interest is
above the noise level and below CCD
saturation.
Check the image min and max in the color bar.
A signal greater than 600 counts and less than
~60,000 counts is recommended. If the signal
level is unacceptable, adjust the exposure
time or binning level.
For more details on the image window, see
Table 3.7
Edit the label information here.
Figure 3.2 Image window & Edit Image Label box
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Living Image® Software User’s Manual
Table 3.7 Image window
Item
Description
Units
Select the measurement units for the image display (counts, photons, or
efficiency) from this drop-down list
Display
Select the image type (for example, overlay) that you want to display from this
drop-down list. For more details on the different types of image displays, see
Figure 5.6, page 57.
Info
Click to display or hide the image label information.
Opens a dialog box that enables you to export the image or thumbnails to a
graphic file (for example, .bmp or DICOM format)
Creates a preview picture of the image or thumbnails that the Living Image
browser displays when the data is selected.
Preview picture of the selected data
Color bar
Shows the minimum and maximum pixel intensities in the image as well as the
color bar. Pixels less than the color bar minimum are not displayed in the
image.Pixels greater than the color bar maximum are displayed in the maximum
color.
Image label
Information about the image that the software automatically records and userspecified information entered in the Edit Image Label dialog box.
33
3. Acquire an Image or Image Sequence
3.5 Manually Setting the Focus
The IVIS Imaging System automatically focuses the image based on subject height (see
page 193). If you do not want to use the automatic focus feature, you can manually set
the focus.
1. In the control panel, choose Manual Focus in the Focus drop-down list.
- The Manual Focus window appears.
2. To mark the center of the camera in the window, put a check mark next to Display
CCD Center.
3. Select the size of the step increment that the stage moves: Coarse, Normal, or
Fine.
4. Click Up or Down to move the stage and change the focus.
5. If necessary, select another F/stop setting from the drop-down list and adjust the
light level using the arrows.
6. Click Update to apply the settings.
- The resulting focal plane (cm above the stage) is automatically entered in the
Subject height box.
7. Click OK when the image is focused.
3.6 Manually Saving Image Data
When you acquire the first image(s) of a session, the autosave feature prompts you to
choose the folder where you want to save image data. During the session, all images
will be saved to this folder. You can change the autosave folder at any time (select
Acquisition →Auto-Save To on the menu bar). If you do not want to use the autosave
feature, you can manually save data.
1. Turn off the autosave feature: select Acquisition on the menu bar and remove the
check mark next to Auto Save.
2. After you acquire an image or image sequence, click the Save button
Alternatively, select File →Save on the menu bar.
34
.
Living Image® Software User’s Manual
3. In the dialog box that appears, select a directory of interest and click OK.
NOTE
The software automatically includes the user ID, and a date and time stamp with the
data.
3.7 Exporting Image Data
You can export the image data in different file formats (for example, .bmp, .dcm).
1. Click the Export Graphics button
.
2. In the dialog box that appears, select a directory, choose a file type, and enter a file
name.
3. Click Save.
NOTE
When you export to DICOM (.dcm) format, a directory that contains the .dcm files and
a SequenceInfo.txt is created at the specified location.
35
3. Acquire an Image or Image Sequence
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36
Living Image® Software User’s Manual
4 Acquire Kinetic Data
Kinetic Acquisition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Viewing & Editing Data (Kinetic Acquisition window) . . . . . . . . . . . . . . . . . . . . 42
Saving Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
The IVIS® Kinetic is ready to acquire kinetic data after the system is initialized and the
CCD camera reaches operating (demand) temperature (locked).
4.1 Kinetic Acquisition
1. Start the Living Image software (double-click the
icon on the desktop).
2. Initialize the IVIS System and confirm or wait for the CCD temperature to lock. For
more details, see page 11.)
3. When you are ready to begin imaging, click Kinetics in the control panel.
- The Kinetic Acquisition window appears.
Figure 4.1 Control panel (top) and Kinetic Acquisition window (bottom)
4. Select the type of data to acquire and set the acquisition parameters. (For more
details on the acquisition parameters, see Table 4.1, page 39.)
37
4. Acquire Kinetic Data
Select the type data to acquire
(luminescent or fluorescent)
After acquisition, choose
the type of data to display
To adjust a setting using thumb
wheel, put the mouse arrow on
the wheel, then click and hold the
mouse button while you move
the mouse arrow left or right.
Figure 4.2 Kinetic Acquisition window
5. Click the
changes to a
button to start acquisition. (After acquisition begins, the button
.)
- The Maximum vs. Time graph plots the maximum signal in each data frame. For
more details on the graph, see page 41.
6. To stop acquisition, click the
Accumulated Signal
button.
The Accumulate option enables you to view increasing signals in real time. If you plan
to accumulate signals, it is recommended that you perform a test acquisition to optimize
settings so that the photographic image, luminescent, or fluorescent signal is not
saturated.
To perform a test acquisition:
1. Confirm that the Accumulate option is selected. Do not select the Auto color scale
option.
2. Start the acquisition (click the
button).
3. If the photographic image is saturated, stop the acquisition (click the
and reduce the photograph light level.
38
button)
Living Image® Software User’s Manual
!
CAUTION
CAUTION! Extended acquisition of saturated images can shorten the life of
the CCD and should be avoided.
4. Restart the acquisition. If necessary, repeat step 3 and step 4.
Table 4.1 Kinetic acquisition settings
Item
Description
Select the type of data to acquire (luminescent or fluorescent) from
this drop-down list. Choose the Overlay option to acquire
photographic images.
Dynamic Range
14 bit - If this option is chosen, the signal intensities range from 0 to
16384 counts per pixel.
16 bit - If this option is chosen, the signal intensities range from 0 to
65536 counts per pixel.
Note: The14 bit dynamic range enables faster imaging.
Exposure Time (msecs) The exposure time for the luminescent image. Shorter exposure
times enable faster frame rates; longer exposure times provide
greater sensitivity. The14 bit dynamic range enables faster imaging
by attaining a higher frame rate at the cost of a smaller dynamic
range.
39
4. Acquire Kinetic Data
Table 4.1 Kinetic acquisition settings (continued)
Item
Description
Binning
Controls the pixel size on the CCD camera. Increasing the binning
increases the pixel size and the sensitivity, but reduces spatial
resolution. Binning a luminescent or fluorescent image can
significantly improve the signal-to-noise ratio. The loss of spatial
resolution at high binning is often acceptable for in vivo images
where light emission is diffuse. For more details on binning, see
Appendix C, page 206.
Recommended binning: 1-4 for imaging of cells or tissue sections, 48 for in vivo imaging of subjects, and 8-16 for in vivo imaging of
subjects with very dim sources.
F/Stop
Sets the size of the camera lens aperture.The aperture size controls
the amount of light detected and the depth of field. A larger f/stop
number corresponds to a smaller aperture size and results in lower
sensitivity because less light is collected for the image. However, a
smaller aperture usually results in better image sharpness and depth
of field.
In kinetic mode, the photographic and luminescent (or fluorescent)
image are acquired at the same F/Stop. For more details on f/stop,
see Appendix C, page 205.
EM Gain
Multiplies the signal in real time. This option is useful for boosting
low signals above the background noise. For kinetic imaging, the EM
gain may be set to 50, 100, or 250. For conventional 16-bit still image
acquisition, EM gain may be set to Off, 50, 100, or 250.
Excitation Filter
A drop-down list of fluorescence excitation filters. For fluorescent
imaging, choose the appropriate filter for your application (GFP,
DsRed, Cy5.5, or ICG). For bioluminescent imaging, Block is
selected by default. If you select Open, no filter is present.
Lamp Level
Sets the illumination intensity level of the excitation lamp used in
fluorescent imaging (Off, Low, High, and Inspect).
Low - This setting is approximately 18% of the High setting.
Inspect -Turns on the illumination lamp so that you can manually
inspect the excitation lamp.
Note: Make sure that the filters of interest are selected in the filter
drop-down lists before you select Inspect. The Inspect operation
automatically positions the selected filters in the system before
turning on the lamp. Subsequent changes to the filter popup menus
will have no effect until another Inspect operation is performed.
40
Photograph Light Level
Controls the brightness of the lights at the top of the imaging
chamber that are used to acquire photographic images.
Accumulate
Select this option to view the cumulative intensity signal in real time.
When this option is chosen, the software computes and visualizes
the cumulative signal in each frame.
Color Scale
Auto - If this option is chosen, the software chooses the color scale
minimum and maximum. Note: Do not choose this option if the
Accumulate option is selected.
Minimum - A user-specified threshold for the color scale minimum
that is applied to the data if the Auto option is not selected. Intensity
signals less than the minimum are not displayed.
Maximum - A user-specified threshold for the color scale maximum
that is applied to the data if the Auto option is not selected.
File Size
Displays the file size of the kinetic stream (.dcm) being acquired. The
file size display is only available in the Kinetic Acquisition panel.
Living Image® Software User’s Manual
Table 4.1 Kinetic acquisition settings (continued)
Maximum vs. Time
Graph
Item
Description
Save
Click to select an option for saving the data:
Save Current Image - Saves the currently selected frame (single
image, photograph, and read bias).
Save Accumulated Image - Saves the accumulated signal for the
selected frames (.tiff).
Save Kinetic Data - Saves all selected photographic, luminescent
or fluorescent images (frames) and the read bias image (.dcm).
The signal is not accumulated.
Done
Closes the Kinetic Acquisition window
The maximum vs. time graph appears when kinetic acquisition begins and plots the
maximum intensity signal in each frame. The graph provides a convenient way to look
for signal trends or select particular frames for viewing.
• Click a point in the graph to view the corresponding image (frame)
• Put the mouse pointer over the graph to view a tooltip that shows the frame
number and time
• Right-click the graph to view the available shortcut menu of graph display options
Figure 4.3 Maximum vs. time graph
41
4. Acquire Kinetic Data
4.2 Viewing & Editing Data (Kinetic Acquisition window)
After stopping acquisition, you can view the data in the Kinetic Acquisition window.
1. To start the playback, click the
changes to
.)
button. (After playback starts, the button
2. To stop the playback, click the
button.
3. To view a particular frame, do one of the following:
• Move the top frame slider or enter a frame number in the box next to the frame
slider
• Click a location in the Maximum vs. Time graph
4. To select a particular range of kinetic data, move the start and end frames selection
handles. Alternately, enter a frame number in the box next to each slider. Only the
selected frames will be played back or saved.
NOTE
Kinetic data (.dcm) can also be edited in the Image window. For more details, see
page 77.
Frame number 121
Current frame number. Enter a new number
or use the top slider to view another frame.
Start frame in a user-specified data range
= Position of the displayed (current) frame
= Position of the start frame
= Position of the end frame
Figure 4.4 Acquisition window
42
Living Image® Software User’s Manual
Viewing Options
After acquisition has been stopped, right-click the image to access a shortcut menu of
viewing options.
Table 4.2 Kinetic view options
Item
Description
Zoom Area
To magnify a particular area, draw a box around the area that you
want to zoom in on, right-click the area and select Zoom Area on the
shortcut menu.
Zoom In
Incrementally magnifies the view.
Zoom Out
Incrementally reduces the magnification.
Reset Zoom
Returns the image to the default display magnification.
Pan View
Enables you to view a different area of a magnified image. To view
another area of the image, choose this option, then click and hold the
pointer while you move the mouse over the image.
Crop Area
To crop the image, draw a rectangle over the area of interest in the
image, then right-click the area in the box and select Crop Area on the
shortcut menu.
Draw Grid
Displays a grid over the frame.
Draw Scale
Displays a scale along the x- and y-axis of the frame.
Insert Tag
Displays a tag with x,y pixel information at a user-selected location of
the image. To insert a tag, right-click a location in the image and
choose Insert Tag on the shortcut menu.
Remove Tag
Removes a user-selected tag from the image.
Remove All Tags
Removes all tags from the frame.
Display Color Bar
Choose this option to display the color bar.
Display Color Min/Max
Choose this option to display the color bar minimum and maximum.
Display Image Min/Max Choose this option to display the minimum and maximum signal.
4.3 Saving Data
The IVIS® Kinetic instrument enables you to acquire a real-time data stream which can
generate very large files. The file size limit for DICOM data is 2GB. Kinetic data
acquisition automatically stops when this file size limit is reached. Table 4.3 shows how
binning conditions affect the total number of frames that can be collected in overlay or
luminescent/fluorescent only mode.
Table 4.3 Frames collected per 1 GB DICOM file
Binning Level
Frame Size
Overlay
Mode
Luminescent or
Fluorescent Only
DICOM File Size
Total Frames Collected
Bin1
2 MB
250
500
Bin2
512 KB
975
1950
Bin 4
128 KB
3900
7800
Bin 8
32 KB
15600
31250
Bin 16
8 KB
62500
125000
1 GB
43
4. Acquire Kinetic Data
To save data:
1. In the Kinetic Acquisition window, click the Save button and select a save option.
Save Option
Description
Save →Current Image
Saves the currently displayed frame.
Save →Accumulated Image
Saves the accumulated signal for the selected frames (.tiff).
Note: It is not necessary to select the Accumulate option to
save an accumulated image.
Save →Kinetic Data
Saves the data (photographic frames, all luminescent or
fluorescent frames, and read bias) in DICOM format (.dcm).
2. In the Edit Image Labels box that appears, enter information for the image label and
click OK. If you do not want to enter label information, click Cancel.
Kinetic Acquisition window
Image window
Tool palette
Edit Image Labels box
Figure 4.5 The Edit Image Labels box, Image window, and tool palette appear when you save
an image or kinetic stream
NOTE
You can edit and analyze kinetic data in the Image window.
44
Living Image® Software User’s Manual
5 Working With Data
Browsing & Opening Data . . . . . .
The Tool Palette & Image Window .
Working With an Image Sequence .
Working With a Single Image . . . .
Viewing Image Information . . . . .
Image Layout Window . . . . . . . .
Adjusting Image Appearance . . . .
Correcting or Filtering Image Data .
Image Information Tools . . . . . . .
Rendering Intensity Data in Color .
Viewing Transillumination Data . .
Viewing & Editing Kinetic Data . . .
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. 45
. 50
. 51
. 55
. 59
. 62
. 63
. 66
. 67
. 74
. 76
. 77
5.1 Browsing & Opening Data
The Living Image® Browser provides a convenient way to browse and preview data,
view information about the data, and open a single image, image sequence or kinetic
data. You can also navigate to data and open it without the browser (see page 49).
Browsing Data
1. Click the Browse button
. Alternatively, select File →Browse from the menu bar.
2. In the Browse for Folder box that appears, select the data of interest and click OK.
NOTE
The next time you start the Living Image software and open the Browse For Folder
box, the software automatically returns to the last folder visited.
45
5. Working With Data
3. The selected data are displayed in the Living Image browser along with the user ID,
label information, and camera configuration information.
- an image
- an image sequence
- a kinetic data
4. Click the + sign to show the images of a sequence. To view data properties, rightclick the item and select Properties on the shortcut menu.
Table 5.1 Living Image® browser
Item
Description
Hide Browse View
Closes the browser table.
Close Preview
Closes the image preview box.
Label Set
A drop-down list of the available label sets which specify image
information (column headers) that is displayed in the Living Image
browser.
Add to List
If you choose this option, the data that you select in the Browse for
Folder box is added to the Living Image browser. If this option is not
chosen, the data that you select in the Browse for Folder box replaces
the contents of the Living Image browser.
Browse
Opens the Browse For Folder box.
Load as Group
Enables you to select particular images that you want to view as a
sequence. The images may be acquired during different sessions.
To select adjacent images in the browser, press and hold the Shift
key while you click the first and last file in the selection.
To select non-adjacent images in the browser:
PC users: Press and hold the Ctrl key while you click the images
in the browser
Macintosh users: Press and hold the Cmd key (apple key) while
you click the images in the browser.
Note: The Load as Group option is only available when two or more
images are selected in the browser.
46
Load
Opens the selected image or image sequence.
Remove
Removes a user-selected image sequence(s) from the browser.
Close
Closes the Living Image browser.
Living Image® Software User’s Manual
Opening Data
You can open data from the Living Image browser, the toolbar, or the menu bar.
Multiple data sets can be open at the same time.
NOTE
To open recently viewed files, select File →Recent Files on the menu bar.
Opening Data from the
Living Image Browser
1. To open data, do one of the following:
• Double-click the data row:
image
sequence
kinetic data
• Right-click the data name and select Load on the shortcut menu
• Select the data row and click Load.
• Double-click the thumbnail
- The image(s) and tool palette are displayed. Open data is highlighted in green in the
browser.
2. To show the images in a sequence, click the + sign next to a sequence (
).
47
5. Working With Data
3. To open all images in a sequence, click the Display All button
window. To close all images, click the Hide button .
in the image
The image window displays thumbnails of
sequence images using a single color table.
Double-click a thumbnail to open the image
For more details on working with a
sequence in the image window,
see page 51.
48
Living Image® Software User’s Manual
Opening Data from the
Menu or Toolbar
1. Click the Open button
menu bar.
on the toolbar. Alternately, select File →Open on the
2. In the Open box that appears,
double-click the file of interest.
Alternately, select the data and
click Open.
File types:
Click*.txt - an image (Living
Image file format)
Sequence*.txt - an image
sequence (Living Image file
format)
*.dcm - kinetic data
NOTE
To open a recently viewed files, select File →Recent Files on the menu bar.
49
5. Working With Data
5.2 The Tool Palette & Image Window
The tool palette contains information about the data and organizes the image analysis
tools. The tools available in the tool palette depend on the type of data that is active
Click to expand a tool.
Figure 5.1 Tool palette
An image, image sequence, or kinetic data set is displayed in an image window.
Multiple image windows can be open at the same time. The options available in the
image window and tool palette depend on the type of image data.
Figure 5.2 Image window, kinetic data
50
Living Image® Software User’s Manual
5.3 Working With an Image Sequence
When you open an image sequence, the image window displays thumbnails of the
images in the collection. A single color table is applied to the images. (For details on
how to open an image sequence using the Living Image browser, see page 47.)
For details on these items, see Table 5.2
Choose Individual to
apply a separate color
scale to each
thumbnail in a
sequence.
Figure 5.3 Image window, sequence view
If DLIT™ or FLIT™ analysis results are loaded, click the 3D View tab to display the 3D
reconstruction of the luminescent sources (IVIS® Imaging System 200 or Spectrum
only). For more details on 3D reconstruction, see page 151.
Figure 5.4 Image window, 3D view
51
5. Working With Data
Table 5.2 Image window, sequence view tab
Item
Description
Units
Choose counts, photons, or efficiency for the image data from the dropdown list. For more details on counts, photons, or efficiency see
Appendix D, page 213.
Use Saved Colors
Choose this option to display an image using the color table that was last
applied to the image data.
Info
Click to show or hide the sequence information.
Click this button to open all images in a sequence.
Click this button to close all open images in the active sequence.
Click this button to open the Edit Sequence window that enables you to
add or remove images from the active sequence. For more details on
editing a sequence, see page 52.
Click this button to acquire a preview of the sequence for display in the
Living Image browser.
Editing an Image Sequence
You can add individual images to a sequence or remove user-specified images from a
sequence.
1. Open the image sequence that you want to edit. (For details on how to open image
data, see page 47).
2. If you plan to add images to the sequence, browse for the images that you want to
add in the Living Image® browser. (For more details on browsing, see page 45.)
Note: Only individual images, not an image sequence, can be added to a sequence.
3. In the image window, click the Edit button
52
.
Living Image® Software User’s Manual
4. In the Edit Sequence box that appears, choose the image(s) that you want to add or
remove from the sequence.
Single images in the
Living Image Browser
5. To add an image to the
sequence, select an
image and click Copy.
Images in the
active sequence
Images that have
been removed from
the active sequence
6. To remove an image from the sequence, select an image and click Retire.
- The image is removed (retired) from the sequence.
7. To restore a retired image to the sequence, select the retired image and click
Reactivate.
8. When you are finished editing the sequence, click Close.
- The updated image sequence is displayed.
Creating an Image
Sequence from
Individual Images
You can create a sequence from images acquired during different sessions.
1. In the Living Image® Browser, browse for the images of interest. (For more details
on browsing, see page 45.)
NOTE
Browse for individual images (which may or may not be part of a sequence), not image
sequences.
53
5. Working With Data
Individual images (highlighted blue in this example) that may or may not be part of a
sequence can be selected for grouping into a new sequence.
Images loaded in the browser as part of a sequence (highlighted pink in this
example). These images cannot be selected for grouping into another sequence.
2. In the browser, select the images that you want to group together.
•To select adjacent images in the browser, press and hold the Shift key while you
click the first and last file in the selection.
•To select non-adjacent images in the browser:
PC users - Press and hold the Ctrl key while you click the images of interest in the
browser.
Macintosh users - Press and hold the Cmd key (apple key) while you click the
images of interest in the browser.
3. Click Load as Group.
- The image thumbnails are displayed together in an image window.
For details on how to save or export the image data, see Chapter 3, page 34.
54
Living Image® Software User’s Manual
5.4 Working With a Single Image
Table 5.3 explains the items in the image window. For details on how to browse data and
open images, see page 45.
Choose the image display units.
Select a display mode from the drop-down list.
To display or hide the image
information, click Info.
Figure 5.5 Image window, overlay display mode
55
5. Working With Data
Table 5.3 Image window
56
Item
Description
Units
Choose counts, photons, or efficiency from the drop-down list for the
image data. For more details on counts, photons, or efficiency see
Appendix D, page 213.
Display
To choose an image display mode in the image window, make a
selection from the Display drop-down list. See Figure 5.6 for examples
of the display modes.
Overlay
A pseudocolor image of luminescent or fluorescent image data displayed
over a grayscale photographic image.
Photograph
A grayscale image that is captured when the IVIS® Imaging System
illumination lights are activated.
Luminescent
A pseudocolor image of the luminescent data captured during an
exposure when the IVIS Imaging System illumination lights are off.
Fluorescent
A pseudocolor image of the fluorescent data captured during an
exposure when the IVIS Imaging System illumination lights are off.
Background
The CCD camera background acquired with the camera shutter closed.
(See Appendix E, page 217.)
Bias
An electronic offset that exists on every pixel. This means that the zero
photon level in the readout is not actually zero, but is typically a few
hundred counts per pixel. The read bias offset is reproducible within
errors defined by the read noise, another quantity that must be
determined for quantitative image analysis.
Saturation Map
Displays image regions that saturated the CCD digitizer in red. ROI
measurements should not be made on saturated regions. ROI
measurements made on image regions that do not contain saturated
pixels are accurate (unless the image is badly saturated).
Structure
A structured light image of parallel laser lines scanned across the
subject. (Available in the IVIS® Imaging System 200 Series and IVIS
Spectrum.) The surface topography of the subject is determined from
the structured light image.
Reference
A structured light image of a white plate that is acquired and stored on
disk prior to instrument installation.
3D View
A three-dimensional rendering of the subject. For more details see
Appendix H, page 247.
Export
Opens the Export Active View As Image box so that the active image
data can be exported (bmp, jpg, png, tiff, or postscript format).
Info
Click to display or hide information about the image in the image
window.
Living Image® Software User’s Manual
Overlay
Photograph
Luminescent
Bias
Structure
Reference
Height Map
3D View
Figure 5.6 Display modes for a single image
The software coregisters the luminescent and photographic image to generate the overlay image.
57
5. Working With Data
Tagging an Image
An image tag displays the x,y pixel coordinates of the location, and the pixel intensity
(z, counts or photons). You can apply a tag at a user-specified location in an image.
To apply a tag:
1. Right-click a location in the image.
2. Select Insert Tag on the short cut menu.
To remove a tag:
1. Position the pointer over the tag.
2. Right-click the image and select Remove
Tag on the shortcut menu.
3. To remove all tags, right-click the image and
select Remove All Tags on the shortcut menu.
To move a tag:
1. Position the pointer over the tag.
2. When the hand tool appears , use a clickand-drag operation to move the tag, then
click the mouse to set the tag location.
- A line between the pixel and the tag identifies
the location associated with the tag.
Organizing Images
When multiple image windows are open, you can organize them in a cascade or tile
arrangement.
To tile the open
image windows,
choose Window →
Tile on the menu
bar.
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Living Image® Software User’s Manual
To organize the image
windows in a
cascade, choose
Window →Cascade
on the menu bar.
5.5 Viewing Image Information
At acquisition, the software captures image information that includes all of the text
information that is associated with every image (for example, camera parameters and
user labels).
Click Info to display the label set information and acquisition information for the image.
Label set
information
&
acquisition
parameters
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5. Working With Data
To view information about an image:
1. Open the image or image sequence of interest. (For details on how to open data,
see page 45).
2. Select View →Image Information on the menu bar.
- The Image Information window appears.
3. To choose an image, make a selection from the Sequences drop-down list and the
Images drop-down list.
Drop-down list of open sequences.
Choose Individual Images from the
list to show the open single images
in the Images drop-down list.
Drop-down list of images in the selected
sequence. Or a list of single images if
“Individual Images” is selected in the
Sequences drop-down list.
Choose the Show All
Sections option to
display all categories
of image information.
4. To view information of interest, select a category in the upper box to show the
associated information in the lower box. For example, select luminescent image in
the upper box to show the luminescent image acquisition parameters.
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Living Image® Software User’s Manual
Editing the Image
Label
You can edit the image label information after acquisition.
1. Open an image.
2. Select Edit →Image Labels on the
menu bar.
3. In the Edit Image Labels box that appears,
edit the information of interest. You can
also select a new label set to apply to the
image or sequence.
4. When you are finished, click OK.
- The image information is updated.
5. Save the image to save the updated image
information.
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5. Working With Data
5.6 Image Layout Window
The Image Layout window provides a convenient way to annotate and save an image
to a graphic file.
1. To open the Image Layout window,
select View →Image Layout
Window on the menu bar.
2. To paste the active image into the
Image Layout window, click the
button.
3. To resize the image, drag a handle
at a corner of the image.
4. To reposition the image in the
window, drag the image.
Table 5.4 Image layout window
Item
Description
Clears the Image Layout window.
Note: If you do not clear the layout (click the button) before you close the
Image Layout window, the same window contents are displayed the next
time the window is opened
Opens a dialog box that enables you to save the Image Layout window
contents to a graphic file.
Pastes the active image in the Image Layout window.
Copies the contents of the Image Layout window to the system
clipboard.
Pastes the contents of the system clipboard to the Image Layout
window.
Rectangle drawing tool
Ellipse drawing tool
Pointer tool
Arrow and line drawing tool
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Living Image® Software User’s Manual
Table 5.4 Image layout window (continued)
Item
Description
Select an the item in the Image Layout window. To move the item to the
front or back in the window, choose an option from the
drop-down list.
Deletes the selected image.
A drop-down list of formatting options for the Image Layout window. For
example, the 2x2 layout style provides 4 separate layout areas in the
window. A different image can be pasted into each layout area.
To apply notes to an image, enter text in the annotation box and press
Enter. Drag the text to the location of interest in the image.
Opens a dialog box that enables you to select a font or edit the font style
and size.
Opens a color palette that enables you to select a font color or specify a
custom font color.
Opens a text editor that enables you to edit the selected text.
5.7 Adjusting Image Appearance
Use the image adjust tools to adjust the appearance of an image (Figure 5.7).
NOTE
Not all tools are available for all image display modes.
Image data
Min & Max
Color bar
Color bar
Min & Max
Figure 5.7 Tool palette, Image Adjust tools
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5. Working With Data
Table 5.5 Image Adjust tools
Item
Description
Click this button to incrementally zoom out on the image (reduces the
image dimensions in the image window). Note: The zoom tools are also
available in the shortcut menu when you right-click the image (Ctrl-click
for Macintosh users).
Click this button to incrementally zoom in on the image (incrementally
magnifies the image in the image window).
Click this button to magnify the area inside a rectangle that you draw using
a click-and-drag operation. (Sets the dimensions of the magnified area
equal to image window dimensions.)
Click this button to return the image to the default display magnification.
Click this button to move a magnified image (pan) in the image window.
For more details, see page 65.
Click this button to hide or display the image min/max information in the
image window
Click this button to hide or display the color scale in the image window
Click this button to hide or display the color scale min/max information in
the image window
Photo
Adjustment
Brightness
Click and move the slider left or right to adjust the brightness of an image
displayed in overlay or photograph mode. Alternatively, enter a brightness
value.
Gamma
Click and move the slider left or right to adjust the gamma of a image
displayed in overlay mode. Alternatively, enter a gamma value. (Gamma is
related to image contrast.)
Opacity
Click and move the slider left or right to adjust the opacity of the
pseudocolor luminescent data of an image displayed in overlay mode.
Alternatively, enter an opacity value.
Color Scale
Min
The minimum pixel intensity associated with the color bar for an image.
Pixels less than the minimum value are not displayed.
Max
The maximum pixel intensity associated with the color bar for an image.
Pixels greater than the maximum value are displayed in the maximum
color.
Limits
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Auto
When this option is chosen, the software sets the Min and Max values to
optimize image display and suppress background noise. The Min and Max
settings can be manually adjusted to further optimize the image display for
your needs.
Full
Choose this option to set the Max and Min values to the maximum and
minimum data values in the image.
Manual
Choose this option to enter Max and Min values for the image display.
Individual
Applies a separate color table to each image in a sequence. Note: This
option is only available when an image sequence is active.
Living Image® Software User’s Manual
Table 5.5 Image Adjust tools (continued)
Item
Description
Color Table
Click the drop-down arrow to select a color table for the image data. (For
more details on color tables, see Pseudocolor Images, page 211.)
Reverse
Choose this option to reverse the selected color table.
Logarithmic Scale Choose this option to apply a log scale to the relationship between
numerical data and the color range in the color table. A log scale increases
the range of meaningful numerical data that can be displayed.
Magnifying or Panning
in the Image Window
To incrementally zoom in or out on an image:
•Click the
or
button. Alternatively, right-click the image and select Zoom In
or Zoom Out on the shortcut menu.
To magnify a selected area in an image:
1. Click the
button. Alternatively, right-click the image and select Area Zoom on the
shortcut menu.
2. When the pointer becomes a +, draw a rectangle around the area that you want to
magnify.
- The selected area is magnified when you release the mouse button.
To reset the magnification (remove magnification):
•Click the
button. Alternatively, right-click the image and select Reset Zoom on
the shortcut menu.
To pan the image window:
1. Click the
button.
2. When the pointer becomes a
mouse.
., click and hold the pointer while you move the
Note: Panning helps you view different areas of a magnified image. If the image has
not been magnified, you cannot pan the image.
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5. Working With Data
5.8 Correcting or Filtering Image Data
Use the Corrections/Filtering tools (Figure 5.8) to subtract background or apply
corrections to the image data. (For more details on sources of background, see
Appendix E, page 217.) You can also apply smoothing and soft binning to the image
data. (For more information on binning and smoothing, see Appendix C, page 205.)
Read Bias Subtraction and Flat Field
Correction are default mandatory
corrections in photons mode. In counts
mode, these corrections can be cleared.
Figure 5.8 Tool palette, Corrections/Filtering tools
Table 5.6 Tool palette, Corrections/Filtering tools
Tool
Description
Read Bias Subtraction/ Select this check box to subtract dark background from the image
data.If a dark charge image is available for the imaging conditions, the
Dark Charge
dark background image, including read bias noise, will be subtracted.
Subtraction
Otherwise, only read bias noise will be subtracted. For more details on
background, see Appendix E, page 217.
Note: In photons mode, dark background subtraction is a mandatory
default. In counts mode, the check box can be cleared.
66
Flat Field Correction
Select this check box to apply a lens correction factor to the image
data. For more details on flat field correction, see Appendix D,
page 216. Note: In photons mode, flat field correction is a mandatory
default. In counts mode, the check box can be cleared.
Cosmic Correction
Select this check box to correct image data for cosmic rays or other
ionizing radiation that interact with the CCD. For more details on
cosmic correction, see Appendix D, page 216.
Adaptive FL
Background
Subtraction
Opens the Photo Mask Setup box that enables you to set the photo
mask for adaptive fluorescent background subtraction. For more
details on adaptive fluorescent background subtraction, see Appendix
F, page 235.
Binning
Specifies the number of pixels in the image data that are grouped
together to form a larger pixel (called soft binning). Binning changes
the pixel size in the image (Figure 5.9). For more details on binning,
see Appendix C, page 206.
Living Image® Software User’s Manual
Table 5.6 Tool palette, Corrections/Filtering tools (continued)
Tool
Description
Smoothing
Computes the average signal of the specified number of pixels and
replaces the original signal with the average signal (Figure 5.9).
Smoothing removes signal noise without changing pixel size.
Note: This type of smoothing is defined differently from the
smoothing performed in the Living Image® software.
Click this button to return the binning or smoothing to the previous
setting and update the image.
Binning at acquisition = 8, no smoothing
Binning = 2, smoothing = 5x5
Figure 5.9 Example of binning and smoothing image data
5.9 Image Information Tools
You can view information about the active image using the Image Information tools
(Figure 5.10).
Figure 5.10 Tool palette, Image Information tools
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5. Working With Data
Table 5.7 Tool palette, Image Information tools
Tool
Description
See Page
Click this button to display a histogram of pixel intensity.
70
Click this button to display a line profile.
71
Click this button to display the distance measurement cursor in
the image window.
72
Click this button to draw and measure a rectangle on an image.
73
Click this button to display/hide a scale on the x and y-axis of the
image window.
Click this button to display/hide a grid the image window.
Choose the units (cm or pixels) for distance measurements in
the image window.
Image
Binning
The binning applied to the image. Note: If soft binning is applied
to the image data, and the binning level is changed from 8 to 16,
the new binning is indicated as 8x2.
Image X,Y
The x,y pixel coordinates of the mouse pointer location in the
image.
Image Data
The intensity (counts or photons) at the pixel location of the
mouse pointer.
69
Crop/Distance
The x,y pixel coordinates at the upper left corner of the crop
tool.
OR
The x,y pixel coordinates at the “A” end of the distance
measurement cursor.
The x,y pixel coordinates at the lower right corner of the crop
tool.
OR
The x,y pixel coordinates at the “B” end of the distance
measurement cursor.
The width and height of the image crop tool.
OR
Δx, Δy from the A to B end of the distance measurement tool.
Distance
The length of the diagonal from corner A to corner B in the
image crop tool.
OR
The length of the distance measurement cursor.
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Living Image® Software User’s Manual
Use the tools to make measurements in an image and view pixel data in different
formats:
Viewing X,Y
Coordinates &
Intensity Data
Image Information
Description
See Page
x,y coordinates and
associated intensity
The x,y pixel coordinates of the mouse pointer location in
the image and the intensity (counts or photons) at that
location.
Histogram
Histogram of pixel intensities in an image.
70
Line profile
Plots a line graph of intensity data at each pixel along a
user-specified horizontal or vertical line in the image
71
69
1. In the Image Information tools, choose Cm or Pixels from the Units drop-down list.
2. Put the mouse pointer over the location of interest in the image.
- The x,y coordinates and intensity data are displayed in the tool palette.
Note: The information is updated when you change the pointer position.
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5. Working With Data
Viewing an Image
Histogram
The image histogram plots a frequency distribution of the pixel intensities in an image.
The software sorts the intensities into groups or bins (x-axis) and plots the number of
pixels per bin (y-axis).
To display the image histogram:
1. Open an image.
2. In the Image Information tools, click the Image
Histogram button
.
Note: By default the Auto min/max range of the image data determines the histogram
range and bins (the software sets the min and max values to optimize image display
and suppress background noise). To display the histogram using the full intensity
range of the image, click Full in the Histogram window.
3. To edit the minimum or maximum bin intensity, enter a new value in the Min Bin
or Max Bin box, or click the
arrows.
4. To edit the number of bins, enter a new value in the # Bins box or click the
arrows.
NOTE
In the Overlay display mode, the histogram plots the luminescent data. To obtain a
histogram of the photograph, select Photograph from the Display drop-down list.
Table 5.8 Histogram window
Item
Description
Full
Displays the histogram using the full intensity range of the image.
Min Bin
The lowest intensity bin.
Max Bin
The highest intensity bin.
# Bins
The total number of bins.
Opens a dialog box that enables you to export the histogram (.csv).
Copies the histogram to the system clipboard.
Opens the print dialog box.
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Living Image® Software User’s Manual
Viewing a Line Profile
The line profile plots intensity (y-axis) at each pixel (x-axis) along a user-specified line
in the image. The line profile is automatically updated when you change the line
position.
NOTE
In the Overlay display mode, the line profile plots the luminescent data. To obtain a
histogram of the photograph, select Photograph from the Display drop-down list.
To display the line profile:
1. Open an image, and in the Image Information tools, click the Line Profile button
.
- A blue line appears on the image and the Line Profile window appears.
2. To view the line profile at another location in the image, put the mouse pointer over
the line. When the pointer becomes a , drag the line over the image. The blue line
determines the pixel intensities that are plotted in the line profile graph.
- The line profile is updated as you move the blue line move over the image.
Table 5.9 Line Profile window
Item
Description
Line
Orientation
Choose Vertical, Horizontal, or Free Hand from the drop-down list to set the
orientation of the line in the image window. The Free Hand orientation enables
you to drag each line segment endpoint to a user- selected position.
Width
Sets the line width.
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5. Working With Data
Table 5.9 Line Profile window (continued)
Item
Description
Position
Line position (pixels).
X Min
Displays the minimum and maximum value of the x-axis. Use the
arrows to
change the x-axis min or max. If photons is selected in the image window, the
x-axis units = pixels. If counts is selected in the image window, the x-axis units
= cm. To display the range available for the Min or Max, place the mouse pointer
over the Min or Max edit box.
X Max
Y Min
Y Max
arrows to
Displays the minimum and maximum value of the y-axis. Use the
change the y-axis min or max. To display the range available for the Y Min or Y
Max, place the mouse pointer over the Min or Max edit box.
Click to reset the X and Y Min and Max values to the defaults.
Full Scale
Select this option to display the full X and Y-axis scales.
Logarithmic Select this option to apply a log scale to the y-axis.
Scale
Enables you to choose the grid line pattern to display in the line profile window.
Exports the line profile data to a .csv or .txt file.
Copies the line profile graph to the system clipboard.
Opens the Print dialog box.
Making Image
Measurements
To measure distance with the measurement cursor:
1. Open an image, and in the Image Information tools, click the Distance
Measurement Cursor button
.
- A measurement cursor (
) appears on the image. The tool palette shows
the position and length of the cursor.
Measurement cursor
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Living Image® Software User’s Manual
2. To change the cursor position or size, drag the A or B end of the cursor to a new
location on the image.
- The measurement information in the tool palette is updated.
3. To hide the cursor, click the
button.
Table 5.10 Measurement cursor position & length
Item
Description
Pixel x,y coordinates of position A on the cursor.
Pixel x,y coordinates of position B on the cursor.
Length of the cursor from A to B (number of pixels), vertical distance
from A to B (number of pixels).
Distance
Length of the cursor from A to B (number of pixels).
To measure distance using the crop box:
1. Open an image, and in the Image Information tools, click the Image Crop button
.
Crop box
position &
dimensions
Crop box
2. When the mouse pointer changes to a +, draw a rectangle on the area of interest.
3. To change the size or position of the crop box, drag a handle
the box.
4. To delete the crop box from the image, click the
at a corner or side of
button.
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5. Working With Data
Table 5.11 Crop box position & dimensions
Item
Description
x,y coordinates at the upper left corner of the box.
x,y coordinates of lower right corner of the box.
Box width and height.
Distance
Length of the diagonal from the upper left to lower right corner of the
box.
5.10 Rendering Intensity Data in Color
The colorize tool renders luminescence or fluorescence data in color, enabling you to
see both intensity and spectral information in a single view. The tool provides a useful
way to visualize multiple probes or scale probe signals that are not in the visible range.
NOTE
The colorize tool is only available if Show Advanced Options is selected in the general
preferences (see page 196).
To view colorized intensity data:
1. Open an image sequence.
In this example, images
were acquired using
different combinations of
excitation and emission
filters. The samples are
quantum dot nanocrystals
(700 or 800 nm).
2. Select Tools →Colorize “sequence name”_SEQ on the menu bar.
- The software renders each luminescent or fluorescent image in color and
combines them into a single image.
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Living Image® Software User’s Manual
3. To access controls for manually
adjusting the color rendition, click
Colorize.
Table 5.12 Colorize tools
Item
Description
Colorize
Color Range
The color map indicates the color range of the selected camera setup
from short to long wavelength. The two sliders determine the lower
and upper limits of the color range that is used to render color. The
parts of the color map outside the selected range are not used in the
color rendering process. By default, the entire color range is
selected.
Filter Range
The wavelength range of the luminescent images in the sequence.
The two sliders determine the lower and upper end of the filter
range. Only the parts of the image that are within the selected
wavelength range are colorized. By default, the entire filter range is
selected.
Color Camera
VIS
Regular camera setup that mainly renders color in the visible range.
It is similar to the color response of a commercial digital camera. NIR
fluorophores appear dark red to invisible using the VIS camera setup.
NIR
A special camera setup that extends the color response into the near
infrared range. Near infrared fluorophores appear red to purple using
the NIR camera setup.
Log Scale
If this option is chosen, the dynamic range of the brightness in the
image is compressed using a log scale. This improves the visibility of
dark areas in the image.
Real Color
If this option is chosen, the colors are rendered using the
wavelengths that directly correspond to the camera setup. For
example, GFP appears green using real color rendering.
If this option is not chosen, the original wavelength range of the
image is modified to include the entire visible wavelength range of
the camera setup. This helps improve the color contrast.
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5. Working With Data
5.11 Viewing Transillumination Data
The transillumination overview feature combines the images of a FLIT sequence (a
fluorescence sequence acquired in transillumination mode) into a single image. All of
the individual fluor signals are stacked over one photograph and the intensity is
summed. One overview is created per filter pair. If two filter pairs were used during
acquisition, then two overview images will be created. All transillumination locations
are displayed simultaneously; a tool tip displays the transillumination position when
you mouse over a transillumination point.
An overview image is displayed in photon units and can be analyzed using the tools in
the tool palette.
1. Open a sequence acquired in fluorescence transillumination mode.
2. Select Tools →Transillumination Overview for xx_SEQ on the menu bar.
- The overview appears.
Sequence view
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Transillumination overview
Living Image® Software User’s Manual
5.12 Viewing & Editing Kinetic Data
In the image window, you can:
• Play kinetic data
• Select and view a particular image
• Select a range of images and extract as a separate kinetic data set
Current image
Current image number (top slider
position). To select a particular
image, enter a new number or
move the top slider.
Start frame (image) in the
selected data range (left
slider position)
Use the bottom sliders to select a
range of data for viewing or export
End frame (image) in the selected data
range (right slider position)
Figure 5.11 Image window, kinetic data
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5. Working With Data
Figure 5.12 Image window, selecting kinetic data for export
Put the mouse arrow over a bottom slider to view a tooltip that shows the number of
selected images (frames)
Table 5.13 Image window, kinetic data
Item
Description
Play
Starts playing kinetic data.
Stop
Stops playing kinetic data.
Edit and Save options Shows or hides the bottom sliders that enable you to select a
range of data and the Extract button that provides save options for
the user-selected image or data.
Accumulate
If this option is chosen, the software computes and displays the
cumulative intensity signal. Choose this option and playback the
kinetic data to visualize accumulations as it happens.
Extract
Click to select a save option for the current image or selected
data.
Extract Current Image Displays the current image in a new image window.The software
prompts you to save the image when you close the image
window.
Extract Accumulated
Image
78
The software computes the cumulative signal for each image
(sum of the signal in all images up to and including the current
image), then displays the cumulative signal of the current image
in a new image window. The software prompts you to save the
image when you close the image window.
Living Image® Software User’s Manual
Table 5.13 Image window, kinetic data (continued)
Item
Extract Kinetic Data
Viewing Kinetic Data
Description
Choose this option if you want to save a particular range of
images. Opens the Browse For Folder dialog box that enables you
to select where to save the selected data.
1. Open the kinetic data.
2. To start playing the kinetic data, click the button. If you want to start the playback
at a particular image, first move the top slider to the starting image, then click the
button.
3. To stop playing data, click the
button.
4. To view the cumulative signal during playback, choose the Accumulate option. If
the accumulated image maximum exceeds the current color scale range, use the
image adjust tools to adjust the color scale.
Editing & Exporting
Kinetic Data
You can select a range of images for export to DICOM format (includes photographs,
intensity signal, and read bias) or to a movie.
1. In the image window, click the
button (Figure 5.12).
2. If you want to select a particular range of data for export, use the frame range
selection to select the data. Use the left slider to select the start image and the right
slider to select the end image in the data range of interest.
- The top slider automatically moves to denote the location of the current image
with respect to the selected data range.
3. To export the selected data to a movie:
a. Click Extract and choose Save as a Movie.
b.In the dialog box that appears, select a folder, enter a name for the movie, and choose
the file format (for example, .mpg4).
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5. Working With Data
Exporting an Image
from a Kinetic Data Set
1. To select an image, move the frame slider or enter a frame number in the spin box.
Export Graphics button
Spin box
Figure 5.13 Image window, selecting an image for export
2. Click Extract and choose Extract Current Image.
- A new image window appears and displays the selected image.
in the
3. To save a snapshot of the current image, click the Export Graphics button
image window. In the dialog box that appears, select a destination folder, enter a
file name, select a file type, and click Save.
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Living Image® Software User’s Manual
6 Working With ROI Tools
About ROIs . . . . . . . . . . . . . . . . . .
ROI Tools . . . . . . . . . . . . . . . . . . .
Measuring ROIs in an Image . . . . . . .
Measuring Background-Corrected Signal
Measuring ROIs in Kinetic Data . . . . . .
Managing ROIs . . . . . . . . . . . . . . .
Managing the ROI Measurements Table
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6.1 About ROIs
A region of interest (ROI) is a user-specified area in an image (Figure 6.1). The ROI tools
enable you to create three types of ROIs: measurement, average background, or subject
ROI (Table 6.1). During a session, the Living Image® software records information about
the ROIs you create and computes statistical data for the ROI measurements. The ROI
Measurements table displays the data and provides a convenient way to review or export
ROI information (Figure 6.1). (For more details, see Managing the ROI Measurements
Table, page 106.)
ROI Measurements table
Figure 6.1 Example measurement ROIs and ROI measurements table
81
6. Working With ROI Tools
Table 6.1 Types of ROIs
Type of ROI
Measurement ROI
Average Background ROI
Measures the signal
intensity in an area of an
image.
Measures the average signal intensity
in a user-specified area of the image
that is considered background.
Note: Using this type of ROI is optional.
If the animal has significant
autoluminescence or autofluorescence,
you can determine a backgroundcorrected signal in a measurement ROI
by subtracting an average background
ROI from a measurement ROI.
Description
Subject ROI
Identifies a subject animal in an
image.
Note: Using this type of ROI is
optional. It provides a convenient
way to automatically associate (link)
a measurement and average
background ROI for backgroundcorrected ROI measurements when
there is significant
autoluminescence or
autofluorescence.
Available ROI
Drawing Methods
• Manual
• Automatic
• Free draw
• Manual
• Free draw
• Manual
• Automatic
• Free draw
Available Shapes
Circle, square, grid, or
contour
Circle or square
Square
NOTE
For a quick guide to drawing a measurement ROI, see page 84.
6.2 ROI Tools
To display the ROI tools:
1. Open an image or image sequence and click ROI Tools in the tool palette.
ROI
tools
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Table 6.2 Tool palette, ROI tools
Item
Description
Click to select the number of circle ROIs to add to the active image.
Click to select the number of square ROIs to add to the active image.
Click to specify the grid pattern for a measurement ROI that you want to add
to the active image. This tool is useful for an image of a multi-well culture
plate or microtiter plate.
Click and select Auto All to automatically draw ROIs in the image using the
auto ROI parameters. Click and select Auto 1 to automatically draw one ROI
at a user-selected location using the auto ROI parameters. For more details
on using the auto ROI features, see page 88.
Click to display the ROI Measurements table or compute intensity signal in an
ROI.
Click to display a drop-down list of options to delete an ROI(s) in the active
image. For more details, see page 105.
Note: These commands do not delete the ROIs that are saved to the system
(listed in the Menu Name drop-down list).
Apply to
Sequence
Choose this option to apply the selected ROI to all images in a sequence.
Type
Choose the ROI type from the drop-down list:
Measurement - Measures the signal intensity in an area of an image.
Average Bkg - Measures the average signal intensity in a user-specified area
of the image that is considered background.
Subject ROI - Identifies a subject animal in an image. The software
automatically associated a measurement and average bkg ROI included in the
same subject ROI. Using this type of ROI is optional.
Save ROIs
Name
The name of the selected ROI set or the default name for a new ROI set.
Delete
Deletes the selected ROI set from the system. Note: This permanently
removes the ROI from the system.
Load
Applies the ROI set selected from the Name drop-down list to the active
image.
Save
Saves the ROI set in the active image.
Note: This is a global save (the ROI is saved to the system) and the ROI set
can be loaded onto any image. If you use the File ➞ Save commands to save
an image that includes an ROI, the ROI is saved with the image only (not a
global save) and is not available for loading onto other images. For more
details, see Saving ROIs, page 104.
Auto ROI
Parameters
Parameters that specify how the auto ROI tool draws an ROI. Note: These
are advanced options that are only available if “Show Advanced Options” is
selected in the general preferences.
Threshold % If the Auto All or Auto 1 method is selected, the Threshold % specifies the
minimum per cent of peak pixel intensity that a pixel must have to be included
in an ROI identified by the software.
Note: After ROIs are drawn on an image, if you modify the Threshold% (move
the slider or enter a new value) the software automatically updates the ROIs.
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Table 6.2 Tool palette, ROI tools (continued)
Item
Description
Lower
Limit
Specifies a multiple (1 to 10) of the color bar minimum that sets the lower
threshold for identifying an ROI. For example, if the lower limit = 2 and the
color bar minimum = 1000 counts, then the auto ROI tool will only draw an
ROI on areas of 2000 counts or greater. This helps create ROIs only in the
visible range.
Minimum
Size
Sets the minimum size of an ROI (measured in pixels). For example if the
minimum size is set at 50, then ROIs created on the image must be greater
than 50 pixels in size.
Preview
If this option is chosen, the software draws the ROI each time a parameter is
changed. ROI parameters can be saved without drawing the ROI.
Use Bkg
Offset
Choose this option to measure background-corrected signal. For more details,
see page 91.
Replace
ROIs
If this option is chosen, all auto ROIs are replaced when new ROI(s) are
created.
Restore
Defaults
Restores the factory-set defaults for the auto ROI parameters.
Save/Load
Click to display or hide the tools that enable you to save, load, or delete auto
ROIs in the active data. Note: The save function saves parameters, the not
actual ROIs. This means that when you load saved auto ROI parameters, the
software draws a new ROI using the saved values (Threshold%, Lower Limit,
Minimum Size).
6.3 Measuring ROIs in an Image
To obtain the intensity signal in a user-specified area of an image, draw a measurement
ROI on the image. There are three ways to draw measurement ROIs:
Quick Guide: Drawing a
Measurement ROI on
an Image or Image
Sequence
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Drawing
Method
Description
See
Page
Manual
Places one or more ROIs (circular, square, or grid shape) on the image.
84
Automatic
The software automatically locates and draws a contour ROI(s) on the
image. To do this, the software locates the peak pixel intensities in the
image and searches the neighborhood around a peak pixel. A pixel is
included in the ROI if the pixel intensity is greater than the threshold%,
a user-specified percentage of the peak pixel intensity.
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Free draw
Draw line segments that define the ROI.
90
These steps provide a quick guide on how to apply a measurement ROI to an image or
image sequence. For more details about measurement ROIs, see page 84.
1. Open an image or image sequence and click ROI Tools in the tool palette.
Living Image® Software User’s Manual
2. In the ROI tools, select Measurement ROI from the Type drop-down list.
3. Click the Contour button
. For an image or image sequence, select Auto All from
the drop-down list. For kinetic data, select Kinetic ROI.
- The software automatically draws measurement ROIs on the image. The ROI
label shows the total intensity in the ROI. If you are working with a sequence,
open an image to view the intensity label. For more details, see page 84.
4. If it is necessary to adjust the
ROI boundaries, change any of
the auto ROI parameters (use
the slider or
arrows):
• Threshold % - Specifies the minimum per cent of peak pixel intensity that a pixel
must have to be included in an ROI identified by the software
NOTE
After the ROIs have been created, right-click an ROI to view a shortcut menu of ROI
commands (Ctrl-click for Macintosh users). The shortcut menu provides easy access
to many functions for managing ROIs and viewing ROI properties.
5. To show the ROI Measurements table, click the Measure button
palette.
in the tool
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The ROI Measurements tab displays data for all ROIs created in images or sequences
during a session (one ROI per row). The table provides a convenient way to review and
export ROI data. For more details on the table, see Managing the ROI Measurements
Table, page 106.
Manually Drawing a
Measurement ROI
1. Open an image or image sequence, and in the ROI tools, select Measurement ROI
from the Type drop-down list.
2. To specify the ROI shape:
a. Click the Circle
, Square
, or Grid button
.
The grid shape is useful for drawing a grid of ROIs on an image of a well plate.
b. On the drop-down list that appears, select the number of ROIs that you want to add to
the image or the grid ROI dimensions.
- The ROI(s) and intensity label(s) appear on the image. If you are working with a
sequence, open an image to show the ROI intensity.
3. Adjust the ROI position:
a. Place the mouse pointer over the ROI. When the pointer becomes a
ROI.
, click the
b. Drag the ROI.
4. Adjust the ROI dimensions:
a. Place the mouse pointer over the ROI. When the pointer becomes a
ROI.
b. Place the mouse pointer over an ROI handle
to resize the ROI.
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so that it becomes a
, click the
. Drag the handle
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NOTE
You can also change the ROI position or size using the adjustment controls in the ROI
Properties box (see Moving an ROI, page 100 and Editing ROI Dimensions,
page 101).
5. Click the Measure button
.
- The ROI measurements and table appear. For more details on the table, see
Managing the ROI Measurements Table, page 106.
Note: For information on how to save ROIs, see page 104.
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6. Working With ROI Tools
Automatically Drawing
Measurement ROIs
The Living Image® software can automatically identify all of the ROIs in an image or
image sequence that meet the auto ROI parameter thresholds or draw one ROI at a userspecified location.
To automatically draw all ROIs detected by the software:
1. Open an image or image sequence, and in the ROI tools, select Measurement ROI
from the Type drop-down list.
2. Click an ROI shape button (Circle
All from the drop-down list.
, Square
, or Contour
) and select Auto
- The ROIs appear on the image or thumbnails.
3. Click the Measure button
.
- The ROI table appears. For more details on the table, see Managing the ROI
Measurements Table, page 106.
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4. Double-click a thumbnail to view the
ROI measurements in the image.
To automatically draw an ROI at a user-specified location:
1. Open an image.
2. Click an ROI shape button and select
Auto 1 from the drop-down list.
- The create tool appears on the
image.
3. Use the ring
to move the create
tool to the location for the ROI.
4. Click Create on the ring tool.
- The ROI appears on the image and
the ROI label displays the
intensity signal.
5. To draw another ROI, repeat step 3
to step 4.
Note: For information on how to save
ROIs, see page 104.
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6. Working With ROI Tools
Drawing an ROI Using
the Free Draw Method
1. Open an image, and in the ROI tools, select the type of ROI that you want to draw
from the Type drop-down list.
2. Click an ROI shape button (Circle , Square , or Contour ) and select Free
Draw from the drop-down list. In this example, the Contour shape
was selected
for the free draw method.
Note: The ROI shapes that are available depend on the type of ROI selected.
3. If you selected:
or
- Use the pointer (+) to draw the ROI.
- Use the pointer (+) to click around the area of interest and draw line segments
that define the ROI. Right-click when the last point is near the first point in the ROI.
Drawing a Subject ROI
A subject ROI identifies a subject animal in an image. It provides a convenient way to
automatically associate (link) a measurement and average background ROI for
background-corrected ROI measurements when there is significant autoluminescence
or autofluorescence. (For more details on background-corrected ROI measurements,
see page 91.) Using a subject ROI is optional.
To draw a subject ROI using the auto ROI feature:
1. Select Subject ROI from the Type drop-down list.
2. Click the
button.
3. Select Auto All.
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To manually draw a subject ROI:
1. Select Subject ROI from the Type drop-down list.
2. Click the
button, and select 1.
3. Position the subject ROI so that it includes the measurement ROI(s) and the
associated average background ROI.
6.4 Measuring Background-Corrected Signal
If a subject has significant autoluminescence or autofluorescence, you can obtain a
background-corrected ROI measurement by subtracting an average background ROI
from a measurement ROI. The software computes:
Background-corrected intensity signal = Average signal in the measurement ROI Average signal in the average background ROI
The Image Adjust tools and zoom feature are helpful for selecting an appropriate area
for an ROI. By setting the image minimum close to zero and zooming in on a
background area in the image, you can determine where naturally occurring background
luminescence or autofluorescence is present. For more details on the Image Adjust tools
and the zoom feature, see Image Layout Window, page 62 and Magnifying or Panning
in the Image Window, page 65.
To measure background-corrected signal:
1. Draw one or more measurement ROIs on the subject. (For more details, see
page 90.)
2. Draw an average background ROI on the subject:
a. Select Average Bkg ROI from the Type drop-down list.
b. Click the Square
or Circle
button and select 1.
- The ROI is added to the image.
For more details on adjusting the ROI position or dimensions, see page 100 and
page 101.
Note: The average background ROI and measurement ROI do not need to be the
same shape or size because the software computes the average intensity signal in
each ROI.
3. Use one of the following three methods to associate the average background ROI
with one or more measurement ROIs.
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6. Working With ROI Tools
Method 1
Draw a subject ROI that
includes the measurement
ROI and the average
background ROI. For details
on how to draw a subject ROI,
see page 90.
Method 2
Right-click the measurement
ROI and select Set BkG ROI
to Bkg X on the shortcut
menu that appears.
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Method 3:
1. Right-click a background ROI and select Properties on the shortcut menu.
2. In the ROI Properties box that appears, click the Bkg ROI tab and put a check mark
next to Use as BKG for future ROIs in.
3. Choose the image name or the Entire sequence option.
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6. Working With ROI Tools
6.5 Measuring ROIs in Kinetic Data
Kinetic ROIs help you track signal sources on an unanesthetized, mobile subject. The
software automatically creates a separate ROI in each frame based on the user-specified
auto ROI settings. As a result, kinetic ROIs are continuously displayed during kinetic
data playback. You can draw a kinetic ROI using any of the methods or shapes in Table
6.1, page 82.
NOTE
Large kinetic data sets may require more time to create, plot, and measure the ROIs
because the software first applies corrections to a frame (specified in the Corrections/
Filtering tool palette), then draws the ROIs in the frame. The process can be aborted
at any time.
Quick Guide: Drawing a
Kinetic ROI
These steps provide a quick guide on how to apply a measurement ROI to kinetic data.
For more details about measurement ROIs, see page 84.
1. Open the kinetic data and click ROI Tools in the tool palette.
2. In the ROI tools, select Measurement ROI from the Type drop-down list.
3. Click the Contour button
and select Kinetic ROI.
- The create tool appears on the image.
4. Use the ring
to move the create tool to the area of the ROI.
NOTE
When drawing kinetic ROIs on kinetic data with multiple sources, it is recommended
that you start with the brightest source, then the next brightest, and so on in order to
create ROIs that can be distinguished based on the signal strength.
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5. Click Create on the tool.
- The ROI and label appear on the image.
6. If it is necessary to adjust the ROI boundaries or change any of the auto ROI
parameters (use the slider or
arrows):
• Threshold % - Specifies the minimum per cent of peak pixel intensity that a pixel
must have to be included in an ROI identified by the software
7. Click Done to hide the create tool.
- The kinetic data playback starts and shows the ROI in each image.
NOTE
After the ROIs have been created, right-click an ROI to view a shortcut menu of ROI
commands (Ctrl-click for Macintosh users). The shortcut menu provides easy access
to many functions for managing ROIs and viewing ROI properties.
8. To measure the ROIs, click the Measure button
in the tool palette.
- The Kinetic ROI Measurements tab shows ROI information for the current image.
9. To view ROI measurements for all images, click the
arrow next to Current Frame
and select All Frames, then click the Refresh button.
Kinetic ROI measurements are
displayed in a separate tab
Plotting Kinetic ROI
Measurements
The kinetic ROI plot provides a convenient way to view and compare kinetic ROI
measurements across user-selected image frames from the same or different kinetic data
sets.
1. Open one or more kinetic data sets.
2. Draw kinetic ROIs on the data sets in which you want to measure and compare
ROIs.
3. In the ROI tools, click the ROI Measurements button
.
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- The ROI measurements dialog box appears.
4. Click the Plot Kinetic ROI Measurements tab.
5. Make a selection from the Measurement Unit and ROI Measurement drop-down
lists.
6. Select a data set and an ROI.
7. Click Plot ROI Measurements.
8. To add other ROI data to the graph, repeat step 6 to step 7.
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6.6 Managing ROIs
In the ROI Properties box, you can view information about an ROI, change the position
of the ROI on the image, and edit the ROI label or line characteristics
Viewing ROI
Properties
To view ROI properties, do one of the following:
•Double-click the ROI of interest.
• Right-click the ROI and select Properties from shortcut menu that appears.
• Select the ROI, then select View →Properties on the menu bar.
The ROI Properties box appears (for more details see Figure 6.2).
•
ROI selected in
the image. To
view properties
for another ROI,
select another
ROI from the
drop-down list.
To view
properties for another ROI:
• Click another ROI in the image. Alternately, select an ROI from the ROI drop-down
list in the ROI Properties dialog box (Figure 6.2).
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6. Working With ROI Tools
ROI selected
in the image
Label name of the ROI
selected above.
Double-click to edit.
Selected image
Drop-down list of
average background
ROIs in the image
Bkg ROI tab
(average background ROI
selected in the image)
Bkg ROI tab
(measurement ROI
selected in the image)
Information about the
ROI selected from the
drop-down list above
Drop-down list
of subject ROIs
in the image
Enter label information
here for the subject ROI
selected above
Subj ROI tab
Info tab
Figure 6.2 ROI properties
The items in the ROI Properties box depend on the type of ROI selected. For more details
see Table 6.3, page 99.
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Table 6.3 ROI properties
Item
Description
ROI
A drop-down list of ROIs in the active image or image sequence. To select
an ROI, double-click the ROI in the image or make a selection from the dropdown list.
ROI Label
Click to edit the selected ROI label name.
Click Number
A drop-down list of open images.
Subj ROI
The Subject ROI tab shows a drop-down list of all subject ROIs in the click
number selected above that can be linked to a user-specified measurement
ROI or average background ROI (selected from the drop-down list at the top
of the dialog box).
BKG ROI
Info tab
The Bkg ROI tab shows a drop-down list shows all average background
ROIs in the click number selected above that can be linked to a userspecified measurement ROI or subject ROI (selected from the drop-down
list at the top of the dialog box).
ID
User-entered information about a subject ROI.
Label
Label name of the selected subject ROI.
Lock Position
Choose this option to lock the position of the ROI selected in the image.
Xc
X-coordinate of the ROI selected in the image.
Yc
Y-coordinate of the ROI selected in the image.
Lock Size
Choose this option to lock the dimensions of the ROI selected in the image.
Width
Width (pixels or cm) of the ROI selected in the image (for more details on
setting the units, see ROI Dimensions, page 107).
Height
Height (pixels or cm) of the ROI selected in the image.
Line Size
Specifies the ROI line thickness. To change the line thickness, enter a new
value or click the up/down arrows .
Line Color
Specifies the color of the ROI line. To select a line color, click the Browse
button .
Done
Click to close the ROI Properties box and apply any new settings, including:
• Linkage between a measurement ROI and subject ROI (for more details,
see Drawing an ROI Using the Free Draw Method, page 90).
• ROI size dimensions or position
• Subject ROI ID information
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6. Working With ROI Tools
Moving an ROI
There are two ways to move an ROI on an image:
• Drag the ROI to a new location
• Edit the settings in the ROI Properties box
NOTE
You cannot move ROIs created using the auto ROI feature.
To drag an ROI:
1. Put the mouse pointer over the
ROI so that it becomes a
arrow.
2. Drag the ROI.
3. Release the mouse button when
the ROI is properly positioned.
To move an ROI using the ROI Properties box:
1. Double-click the ROI in the image.
- The ROI Properties box appears and displays the
position and dimensions of the selected ROI.
2. To set ROI position, enter new Xc (pix) and Yc (pix)
values in the ROI Properties box.
3. To rotate the ROI clockwise, enter the degrees in the
Angle (deg) box and click outside the box.
4. To lock the current ROI position, choose the Lock
Position option.
Note: The ROI position cannot be changed until the
Lock Position option is cleared.
Position of the ROI selected in the image
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Editing ROI
Dimensions
There are two ways to resize a circle or square ROI:
• Drag a handle on the ROI.
• Edit the settings in the ROI Properties box.
NOTE
You cannot change the size of an ROI that was created using the auto ROI or free
draw tool.
To resize an ROI using a handle:
1. Select the ROI and place the
pointer over a handle ( )on the
ROI.
2. When the pointer becomes a
arrow, drag the handle.
To resize an ROI using the ROI Properties box:
1. Double-click the ROI in the image.
- The ROI Properties box appears and displays the
positions and dimensions of the selected ROI.
2. Enter a new width or height value in the ROI
Properties box.
3. To lock the current ROI size, choose the Lock Size
option.
Note: The ROI size cannot be changed until the
Lock Size option is cleared.
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6. Working With ROI Tools
Editing the ROI Line
1. Double-click the ROI that you want to edit.
- The ROI Properties box appears.
2. To edit the ROI line thickness, enter a new value in
the Line Size box. Alternately, click the
arrows.
3. To change the ROI line color:
a. Click the Browse button
.
- The Select Color box appears.
b. To select a basic color for the ROI line, click a basic
color swatch, and click OK.
c. To define a custom color, drag the crosshair in the
custom color field, adjust the brightness slider, and
click Add to Custom Colors.
d. To select a custom color for the ROI line, click a
custom color swatch, and click OK.
Brightness slider
Cross hairs in the custom color field
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Moving or Editing an
ROI Label
To move an ROI label:
1. Place the pointer over the
ROI label.
2. When the pointer becomes
a , drag the label.
3. Click to release the label at
the new location.
To edit an ROI label:
1. Double-click the ROI. Alternately, right-click the ROI (Ctrl-click for Macintosh users)
and select Properties on the shortcut menu.
2. In the ROI Properties box that appears, edit the name in the ROI Label box and click
Done.
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Saving ROIs
The software automatically saves ROIs with an image. The ROI measurements are
saved to the AnalyzedClickInfo.txt file associated with the image. ROIs are saved per
user and can be applied to other sequences.
-
To save ROIs to the system:
1. In the Name drop-down list, confirm the default name or enter a new name for the
ROI(s).
2. Click Save.
- The ROI(s) from the image are saved to the system and can be selected from the
Name drop-down list.
To load ROIs on an image:
1. Open an image.
2. In the ROI tools, make a selection from the Name drop-down list and click Load.
Note: If you load ROI(s) onto an image, then draw additional ROIs, the Save button
changes to Overwrite. If you want to save this collection of ROIs using the existing
name, click Overwrite.
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Deleting ROIs
You can delete ROIs from an image or permanently remove ROIs from the system.
To delete ROIs from an image:
1. In the ROI tools, click the
button.
2. Make a selection from the drop-down list of delete commands.
- The specified ROIs are deleted from the image.
Note: This does not delete ROIs saved to the system (global save).
To permanently remove ROIs from the system:
1. Select the ROI(s) that you want to delete from the
drop-down list of saved ROIs.
2. Click Delete.
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6.7 Managing the ROI Measurements Table
The ROI Measurements table shows information and data for the ROIs created during
a session. The ROI measurements can be displayed in units of counts or photons, or in
terms of efficiency. For more details, see Quantifying Image Data, page 213.
To view the ROI Measurements table, click the
ROI Measurements on the menu bar.
button. Alternately, select View →
Column headers in the table include ROI information, ROI
measurements and dimensions, and information about the
image recorded at acquisition.
Select the type of ROI or image data to include in the table
Grid ROIs are displayed in
a separate tab
Kinetic ROIs are displayed
in a separate tab
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Table 6.4 ROI Measurements table
Item
Description
Measurement
Types
Make a selection from the drop-down list to specify the type of ROI
measurements to include in the table.
None
Exclude ROI measurements from the table.
Counts
Includes Total Counts, Avg Counts, Stdev Counts, Min Counts, and Max
Counts in the table.
Total Counts = the sum of all counts for all pixels inside the ROI.
Avg Counts = Total Counts/Number of pixels or super pixels.
Stdev Counts = standard deviation of the pixel counts inside the ROI
Min Counts = lowest number of counts in a pixel inside the ROI.
Max counts = highest number of counts in a pixel inside the ROI.
(For more details on count units, see page 213.)
Note: These numbers are displayed if the units selected in the ROI
Measurements table and the image are the same. Otherwise, N/A appears in
each column.
Photons
Total Flux = the radiance (photons/sec) in each pixel summed or integrated
over the ROI area (cm2) x 4π.
Average Radiance = the sum of the radiance from each pixel inside the ROI/
number of pixels or super pixels (photons/sec/cm2/sr).
Stdev Radiance = standard deviation of the pixel radiance inside the ROI
Min Radiance = lowest radiance for a pixel inside the ROI.
Max Radiance = highest radiance for a pixel inside the ROI.
(For more details on photon units, see page 214.)
Efficiency
Image
Attributes
Available for fluorescent images only. Includes Total Efficiency, Average
Efficiency, Stdev Efficiency, Min Efficiency, and Max Efficiency in the table.
(For more details on efficiency, see page 213.)
Make a selection from the drop-down list to specify the click number (image
file) information to include in the table. Click attributes include label name
settings and camera settings.
None
Excludes image attributes from the table.
All
Possible
Values
Includes all of the image attributes (for example, label name settings and
camera settings) in the table.
All
Populated
Values
Includes only the image attributes with values in the table.
Xenogen
Universal
Includes all Xenogen label name settings in the table.
ROI
Dimensions
Make a selection from the drop-down list to specify the ROI dimensions to
include in the table.
None
Excludes the ROI area, x,y-coordinates, and dimensions from the table.
Pixels
Includes ROI area, x,y-coordinates, and dimensions (in pixels) in the table.
cm
Includes ROI area, x,y-coordinates, and dimensions (in cm) in the table.
Copy
Selected
Copies the selected row(s) in the table to the system clipboard.
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Table 6.4 ROI Measurements table (continued)
Item
All
Description
Copies all rows in the table to the system clipboard.
Refresh
Updates the table.
Configure
Displays the Configure Measurements box that enables you to specify and
organize the data categories (column headers) for the table.
Export
Displays the Save Measurements box so that the data can be saved to a .txt
or .csv file.
Note: Grid ROI measurements exported to a .csv file can be opened in a
spreadsheet application like Microsoft® Excel®.
Close
Configuring the ROI
Measurements Table
Closes the ROI Measurements table.
You can customize the data and information (column headers) in the ROI
Measurements table. Several predefined categories are available in the Measurement
Types, Click Attributes, and ROI Dimensions drop-down lists.
1. To reorder the columns, drag a column header (left or right) in the table.
2. To change the measurement units, make a selection from the Measurement Types
drop-down list.
3. To include image information in the ROI table, make a selection from the Image
Attributes drop-down list.
4. To include ROI dimensions in the table, select units (Pixels or cm) from the ROI
Dimensions drop-down list.
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To create & save a custom table configuration:
1. In the ROI Measurements table, click Configure.
- The Configure Measurements box appears.
Click to reorder the
available items in
ascending or descending
alphabetical order
Available items (column headers)
that can be added to the table
Items (column headers)
currently in the table
2. Do either of the following:
•Select a configuration that you want to modify from the User Lists drop-down
OR
•Select Customized (Unsaved) from the User Lists drop-down to create a new
configuration
3. To add an item to the table, click an item in the Available Item list and then click
Add.
4. To remove an item from the table, select the item that you want to remove in the
Selected Items list, and click Remove.
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6. Working With ROI Tools
5. To reorder an item in the Selected Items list, select the item and click Move Up or
Move Down.
- The columns in the ROI Measurements table are updated.
6. To save the table configuration, enter a name in the Name box and click Save.
Note: You cannot overwrite a factory loaded configuration. If you modify a factory
loaded configuration, save it to a new name.
To delete a custom table configuration
1. Select the configuration from the User Lists drop-down and click Delete.
2. Note: Factory loaded table configurations cannot be deleted.
Copying or Exporting
the ROI Measurements
Table
To export the table:
1. Click Export.
2. In the dialog box that appears, select a folder and enter a name for the file (.txt),
then click Save.
To copy the table to the system clipboard:
• Selected rows - Select the rows of interest and click Selected. Alternatively, select
the rows then right-click the table and choose Copy Selected on the shortcut menu.
• All rows - Click All. Alternately, right-click the table and select Copy All on the
shortcut menu.
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7 Image Math
Using Image Math to Create a New Image . . . . . . . . . . . . . . . . . . . . . . . . . 112
Subtracting Tissue Autofluorescence . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
Overlaying Multiple Images . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118
The Living Image® software provides tools that enable you to mathematically combine
two images to create a new image. The primary use of image math is to subtract tissue
autofluorescence background from signal.
LIving Image Tool Use This Tool To...
See Page
Image Math
Mathematically combine (add, multiply, subtract, or divide)
two user-specified images.
112
Image Math
Remove autofluorescence from a fluorescent image.
115
Image Overlay
Coregister multiple fluorescent or luminescent images on the
same photographic image to view multiple reporters in a
single image.
118
To perform image math, open an image sequence (see page 47) or a group of images
(see Creating an Image Sequence from Individual Images, page 53).
111
7. Image Math
7.1 Using Image Math to Create a New Image
To create a new image using image math:
1. Load an image sequence.
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Living Image® Software User’s Manual
2. Select Tools →Image Math for xx_SEQ on the menu bar.
3. In the Image Math window that appears, select an image of interest from box A and
box B.
- The Image Math window shows a thumbnail of image A, image B, and the new
image.
Note: For more
details on items in
the Image Math
window, see Table
7.1, page 114.
4. Select a mathematical function from the Result drop-down list.
5. To include a scaling factor (k) in the function, enter a value for k.
6. To view the new image, click Display Result for Measuring.
New image generated
by the Result function
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7. Image Math
To save the new image:
1. Click the Save button
. Alternatively, select File →Save on the menu bar.
2. In the dialog box that appears, select a directory, and click Save.
- A folder of data is saved to the selected location (AnalyzedClickInfo.txt,
ClickInfo.txt, luminescent and photographic TIF images).
To export the image to a graphic file:
1. Click the Export button
.
2. In the dialog box that appears, select a directory, enter a file name, and select the
file type from the Save as type drop-down list.
3. Click Save.
Table 7.1 Image Math window
Item
Description
Color Ranges for A and B
Full
Choose this option to set the Max and Min values to the
maximum and minimum data values in the image.
Auto
When this option is chosen, the software sets the Min and
Max values to optimize image display and suppress
background noise. The Min and Max settings can be manually
adjusted to further optimize the image display for your needs.
Note: The color bar scale does not affect the image math
result.
Color Ranges for Result
Image
Full
See above.
Auto
See above.
Min = 0
Choose this option to set the minimum data value to zero.
Results
Drop-down list of mathematical functions that can be used to
generate the new image, including:
A - B*k
A + B*k
A * B*k
A/B if Counts(B)>k (Useful for fluorescence tomography.)
114
k, Image Math window
A user-specified scaling factor applied in the results function.
k, Fluorescent Background
Subtraction window
The software computes k = the ratio of the autofluorescent
signal measured using the background filter to the
autofluorescent signal measured using the excitation filter in a
region on the animal where no fluorophore is present.
Compute ‘k’ from ROI
This option is useful for subtracting fluorescence background.
Draw the same ROI in both images on an area considered
background. In the “Compute ‘k’ from ROI” drop-down list,
select the same ROI in each image.
with Photo from
Choose this option to display the new image in overlay mode
using the selected photographic image. (This option is only
available if one of the selected images is an overlay.
Living Image® Software User’s Manual
Table 7.1 Image Math window (continued)
Item
Description
Display Result for Measuring
Opens the image generated by image math in an image
window.
7.2 Subtracting Tissue Autofluorescence
To remove tissue autofluorescence from image data, the IVIS® Imaging System
implements a subtraction method using blue-shifted background filters that emit light at
a shorter wavelength (Table 7.2).
Table 7.2 Emission, excitation, and background filters used to acquire data that can be corrected
for tissue autofluorescence
Emission Filter
Excitation Filter (Primary
Image)
Fluorophore
Background Filter
(Background Image)
Passband (nm)
GFP
515-575
445-490
410-440
DsRed
575-650
500-550
460-490
Cy5.5
695-770
615-665
580-610
ICG
810-875
710-760
665-695
The objective of using a background filter is to excite the tissue autofluorescence
without exciting the fluorophore. To reduce autofluorescence signal in the primary
image data, use the image math tool to subtract the background filter image from the
primary excitation filter image. For more details on tissue autofluorescence, see
Appendix F, page 236
The software computes:
Background-corrected signal = (A - B) × k, where:
A = primary image (acquired using the excitation filter)
B = background image (acquired using the background filter)
k = (primary signal/background signal)
The background signal is obtained from a measurement ROI that is
located in an area where no fluorophore signal is present. The scale factor
k accounts for different levels of tissue autofluorescence due to different
excitation wavelengths and filter transmission characteristics.
After you acquire an image sequence that includes a primary and background image, use
the image math tool to subtract tissue autofluorescence. (For more details on acquiring
an image sequence, see Chapter 3, page 22.)
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7. Image Math
To subtract tissue autofluorescence:
1. Load the image sequence that includes the primary and background fluorescent
images.
2. Open either the primary or background image and:
a. Optimize the image display using the color scale Min and Max sliders in the Image
Adjust tools.
b. Draw a measurement ROI on an area of the animal that represents background signal
(area where no fluorophore signal is present).
Note: You only need to draw the ROI on one of the images. The software copies
the ROI to the other image.
3. Select Tools →Image Math for xx.SEQ on the menu bar.
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Living Image® Software User’s Manual
4. In the Image Math window that appears, select the primary image in box A. Select
the background image in box B.
Note: For more details on items in the Image Math window, see Table 7.1, page 114.
5. Select the math function 'A-B*k' in the Result drop-down list.
6. Click
and select the ROI (created in step 2) from the drop-down list.
- The background-corrected signal is displayed.
7. To view the mathematical result (overlay mode) in a separate image window, click
Display Result For Measuring.
Note: If necessary, use the Color Scale Min and Max sliders in the Image Adjust
tools to adjust the image display.
To save the new image:
1. Click the Save button
. Alternately, select File →Save on the menu bar.
2. In the dialog box that appears, select a directory, and click Save.
- A folder of data is saved to the selected location (AnalyzedClickInfo.txt,
ClickInfo.txt, luminescent and photographic TIF images).
To export the new image to a graphic file:
1. Click the Export button
.
2. In the dialog box that appears, select a directory, enter a file name, and select the
file type from the Save as type drop-down list.
3. Click Save.
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7. Image Math
7.3 Overlaying Multiple Images
The image overlay tool provides a convenient way to view multiple reporters in one
image. You can use the image overlay tool to display multiple luminescence or
fluorescence images on one photographic image. To do this:
To coregister multiple images:
1. Acquire an image sequence using the appropriate filters for each reporter.
Alternately, create a sequence from images acquired during different sessions. (For
more details, see page 53.)
2. Open the image sequence.
Note: To view all
images in the sequence,
click the Display All
button
to open each
image (overlay mode) in
a separate image
window.
3. Open one of the images and optimize the image display using the color scale Min
and Max sliders in the Image Adjust tools.
4. Select Tools→Image Overlay for xx_SEQ on the menu bar.
- The image overlay window appears and shows the first photographic image in the
sequence.
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Living Image® Software User’s Manual
5. Select a photographic
image in the upper box.
6. To select all of the fluorescent or luminescent images in the lower box, click the
button.
Alternately, to select particular images, do either of the following:
• To select non-adjacent images in the list, press and hold the Ctrl key while you
click the images.
OR
• To select adjacent images in the list, press and hold the Shift key while you click
the first and last image in the selection.
- In the overlay that is generated, the signal in each image is assigned a different
color table. The photographic image is at the bottom of the stack and the last
fluorescent or luminescent image selected from the list is at the top of the stack.
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7. Image Math
7. To remove all fluorescent or luminescent images from the overlay, click the
button.
8. To change the display of a fluorescent or luminescent image in the overlay:
a. Select the image in the lower box.
b. Choose the Edit Layer Properties option.
c. Adjust the opacity, select a different color table, or edit the color table properties. When
finished, clear the Edit layer Properties option.
Select white or black for the
low end of the color scale
Set the number of color scales
displayed per column
9. To reorder the images in the list:
a. Choose the Edit Layer Properties option.
b. Select an image.
c. Click the
or
arrows.
10.To copy the overlay image to the system clipboard, click the Copy button
11.To export the overlay image to a graphic file, click the Export button
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.
.
Living Image® Software User’s Manual
8 Planar Spectral Image Analysis
Planar Spectral Imaging Tools . . . . . . . .
Planar Spectral Image Analysis . . . . . . . .
Viewing & Exporting Graphical Results . . .
Managing Planar Spectral Imaging Results .
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125
126
The Living Image® software enables you to apply planar spectral image analysis to a
sequence to determine the average depth and total photon flux of a bioluminescent point
source in a user-specified region of interest. For more information on planar spectral
image analysis, see Appendix G, page 239.
Use the imaging wizard to setup the image sequence required for planar spectral image
analysis. (For more details on the imaging wizard, see page 24.) At a minimum, the
sequence must include a photographic and luminescent image at the first wavelength
and a luminescent image at a second wavelength (560-660).
8.1 Planar Spectral Image Analysis
1. Open the image sequence that you want to analyze.
2. In the tool palette, click Planar Spectral Imaging.
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8. Planar Spectral Image Analysis
3. In the Analyze tab, select the emission filter
wavelengths for the analysis.
It is recommended that you do not include a
wavelength in the analysis if the signal is less than
or equal to the autoluminescent background. If
autoluminescent background is a concern, you can
create a background ROI and link it to the
measurement ROI prior to planar spectral analysis.
(For more details, see Measuring BackgroundCorrected Signal, page 91.)
4. In the ROI List drop-down, select All or a particular
ROI for the analysis. If there is no measurement
ROI, draw an ROI that includes the area for
analysis. (For more details on drawing ROIs, see
Measuring ROIs in an Image, page 84.)
You only need to draw the ROI(s) on one image in
the sequence. The software copies the ROI(s) to all
other images of the sequence during the analysis.
The ROI should include as much of the light
emission from a single source as possible.
5. Choose the tissue properties:
a. In the Properties tab, make a selection from the
Tissue Properties drop-down list.
b. Choose the tissue type most representative of the
area of interest. Muscle is a good choice for a
generic tissue type.
- The software automatically sets the internal medium index of
refraction based on the selection in the Tissue Properties list.
6. Make a selection from the Source Spectrum dropdown list.
7. Click Analyze in the Analyze tab.
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Living Image® Software User’s Manual
The Results tab displays the computed average depth
(mm) and total flux (photon/sec) of the bioluminescent
point source in the specified ROI(s).
8.2 Planar Spectral Imaging Tools
The planar spectral imaging tools are displayed in three tabs.
Figure 8.1 Tool palette, planar spectral imaging tools
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8. Planar Spectral Image Analysis
Table 8.1 Planar spectral imaging tools & results
Item
Description
Analyze Tab
Sequence
Name of sequence used for the analysis.
Tissue, Source
The tissue properties and source spectrum selected in the
Properties tab.
Select Filters
In the Filter box, select the acquisition wavelengths for the images
in the selected sequence. To select non-adjacent wavelengths,
press and hold the Ctrl key while you click the wavelengths.
(Macintosh users, press and hold the Cmd key while you click the
wavelengths.)
ROI List
A drop-down list of the ROIs in the active image.
Analyze
Click to perform the spectral analysis.
Properties Tab
Tissue Properties
Drop-down list of the absorption and scattering properties of
various tissues.
Internal medium
index of refraction
Tissue index of refraction that is automatically specified when you
select a tissue property.
Source Spectrum
Drop-down list of bioluminescent sources.
Plot
Tissue Properties
Click to display graphs (cm-1 vs nm) of the absorption coefficient
(μa), effective attenuation coefficient (μeff), and reduced scattering
coefficient (μ’s).
Source Spectrum
Click to display the spectrum of the selected bioluminescent source
(intensity versus wavelength, normalized to one).
Results Tab
Spectral Results
ROI
Name of the analyzed ROI.
Depth (mm)
Estimated depth of the point source.
Total Flux (phot/s)
Estimated total photon flux from the point source.
Plot Linear Fit
Displays a graph of normalized intensity versus the effective
attenuation coefficient (μeff, the optical property of the tissue
selected in the Tissue Properties drop-down list) along with the
linear fit to these data determined by the spectral analysis code.
Plot Intensity
Displays a graph of normalized intensity versus wavelength.
Intensity is normalized by the selected source spectrum and filter
transmission properties.
Export
Opens a dialog box that enables you to save the results to a text file
(.txt).
Save Results
Name
124
A drop-down list of saved results. Includes the default name for
new unsaved analysis results (SpIm_xx).
Delete
Deletes the selected results.
Load
Opens the selected results.
Save
Saves the analysis results (results name appears in the Name dropdown list).
Living Image® Software User’s Manual
8.3 Viewing & Exporting Graphical Results
To view a graph of the results:
1. In the Results tab, select an ROI.
2. Click Plot Intensity or Plot Linear Fit.
The linear fit graph plots the logarithm of the intensity, normalized to the selected
source spectrum and the filter transmission properties, against the optical property of
the tissue (μeff). The slope of the line is the source depth. If any of the measured points
(in red) deviate significantly from the straight line fit, then the analysis results may be
suspect. The horizontal error bars represent the uncertainty in the optical properties
(usually estimated at ±10%). The vertical error bars represent noise in the image.
The intensity graph displays a graph of the measured intensity in the selected ROI at
each wavelength in the analysis. The intensity is normalized to the selected source
spectrum and the filter transmission properties.
To export graph data:
1. Click the Export Data button
.
2. In the dialog box that appears, select a directory for the data and enter a file name
(.csv).
The data can be opened in a spread sheet application such as Microsoft® Excel®.
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8. Planar Spectral Image Analysis
8.4 Managing Planar Spectral Imaging Results
To save results:
1. Select the results of interest (Splm_xx) from the
Name drop-down list
2. Click Save.
- The planar spectral imaging results are saved
with the image.
To view results:
1. Select the results of interest from the Name dropdown list.
2. Click Load.
To delete results:
1. Select the results that you want to delete from the
Name drop-down list.
2. Click Delete.
To copy selected results:
1. Right-click the results (row) of interest and select
Copy Selected from the shortcut menu that
appears.
- The selected results are copied to the system
clipboard.
To copy all results:
1. In the Results tab, right-click the results table and
select Copy All from the shortcut menu that
appears.
- All of the results table is copied to the system
clipboard.
To Export Results:
1. Right-click the results table and select Export
Results from the shortcut menu that appears.
2. In the dialog box that appears, choose a folder for
the results, enter a file name (.txt), and click Save.
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Living Image® Software User’s Manual
9 Spectral Unmixing
Spectral Unmixing . . . . . . . . . .
Spectral Unmixing Results Window
Spectral Unmixing Parameters . . .
Spectral Unmixing Options . . . . .
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131
132
134
The Living Image® software uses spectral unmixing to distinguish the spectral
signatures of different fluorescent or bioluminescent reporters and calculate the
respective contribution of each on every pixel of an image. Use spectral unmixing to:
• Extract the signal of one or more fluorophores from the tissue autofluorescence.
Images can be acquired using epi-illumination (excitation light above the stage) or
transillumination (excitation light below the stage)
• Analyze bioluminescence images when more than one reporter is used in the same
animal model
Use the imaging wizard to setup the image sequence required for spectral unmixing.
(For more details on the imaging wizard, see page 24.) If you do not use the imaging
wizard to set up the image sequence, it is recommended that the image sequence include
images acquired using several filters that sample the emission or excitation spectra at
multiple points across the entire range. Make sure that the band gap between the
excitation and emission filters is sufficiently large (for example, >40 nm) so that the
excitation light does not leak through the emission filter where it can be detected by the
CCD.
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9. Spectral Unmixing
9.1 Spectral Unmixing
1. Load the image sequence.
In this example, the fluorophore is Quantum Dots 800. Images were acquired using
a 675 nm excitation filter and emission filters from 720 to 820 nm in 20 nm
increments.
2. In the Analyze tab of the Spectral Unmixing tools, put a check mark next to the emission
wavelengths that you want to include in the analysis.
Excitation
wavelength
Emission
wavelengths of
the sequence
3. In the Components drop-down list, select the
number of spectral components to unmix in the
images (the number of fluorophores +1 since
tissue autofluorescence accounts for 1
component).
For example, if the image data includes one
fluorophore, then there are two components to
unmix−the fluorophore signal and the tissue
autofluorescence.
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Living Image® Software User’s Manual
4. Make a selection from the Mask drop-down list:
• Photo - Opens the Photo Mask Setup window.
The purple mask specifies the area for
analysis.
a. Use the Threshold slider or
arrows to
adjust the mask so that it matches the
underlying subject photograph as closely as
possible without including any area outside
the subject image.
b. Click Set.
• All - The entire image is analyzed. This option
is not recommended. It introduces many offtarget pixels that might mislead and
significantly slow down the analysis
• ROI - ROIs applied to the sequence are available in the drop-down list. Select an
ROI to analyze just the area in the ROI. This option is recommended for well
plates or dark objects where it is hard to achieve a good mask from the
photograph.
5. In the tool palette, click Unmix Spectra.
- The spectral unmixing results appear. The Distribution tab shows a photon
density map of each unmixed result and a composite image that includes all of
the fluorescent signals, each displayed in a different color.
Unmixed 1 = Autofluorescence
Composite = Unmixed 1 + Unmixed 2
Unmixed 2 =
Fluorophore signal
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9. Spectral Unmixing
6. To analyze an unmixed image, double-click the image.
- The image appears in a separate image window and the tool palette is available.
This enables you to make ROI measurements and image adjustments that are
saved with the image.
7. To view the composite image
separately, double-click the
composite image.
- The Composite tab displays the
composite image. This enables
you to export, print, or copy the
composite image to the system
clipboard.
Item in the
Concentration Plot
Description
Click to show the controls to adjust the fluorescence opacity and the
color table display in the concentration plot. Click anywhere in the
window to hide the controls.
Show Labels
130
Choose this option to display image labels on the concentration plot
and composite image.
Living Image® Software User’s Manual
9.2 Spectral Unmixing Results Window
The results are displayed in the three tabs of the Spectral Unmixing Results window.
Spectra Tab
The spectrum plot shows the normalized spectra of the unmixed results. You can edit
the appearance of the spectrum plot using the tools in the spectral unmixing tool palette
(Spectrum tab) (Figure 9.1).
A list of the spectra in the results. Add/remove a check mark to show/hide the
spectrum in the spectrum plot. Click a spectrum (row) to display in the preview pane.
Spectrum Plot
Figure 9.1 Spectral unmixing tools and spectrum plot
Table 9.1 Tool palette, spectral unmixing tools
Item
Description
Opens a dialog box that enables you to select a spectrum to add to the
spectrum plot.
Opens a dialog box that enables you to edit a spectrum in the spectrum
plot. Note: You can also double-click a spectrum row in the tool palette
(Spectrum tab) to open the dialog box.
Deletes the spectrum from the spectrum plot
Type
The type of spectrum.
131
9. Spectral Unmixing
Table 9.1 Tool palette, spectral unmixing tools (continued)
Item
Description
SOL
A spectrum generated by the spectral unmixing algorithm.
ROI
A spectrum calculated for a user-selected ROI.
LIB
A user-selected library spectrum. The library includes spectra obtained of
different sources obtained using excitation and emission filters.
Name
The spectrum identifier used by the unmixing algorithm. The name
cannot be modified.
Label
The spectrum name in the spectrum plot key. The label can be edited.
Color
The color of the spectrum in the spectrum plot. For the SOL type
spectrum, it is also the color in the composite image.
Spectrum Preview
Shows the spectrum selected above (click a row above the preview
pane).
Use this tool to pick up a pixel in an opened image and plot the spectrum
at this pixel in the spectrum preview.
9.3 Spectral Unmixing Parameters
The Results tab in the Spectral Unmixing tool palette shows the optimized fit
parameters used by the software to derive the spectral unmixing results (Figure 9.2).
Figure 9.2 Tool palette, Spectral unmixing tools, Results tab
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Living Image® Software User’s Manual
Table 9.2 Spectral unmixing tools, Results tab
Item
Description
Number of Iterations The number of iterations that the algorithm used.
Number of
Components
The number of components unmixed.
Number of
Wavelengths
The number of wavelength pairs used in the analysis.
Number of Samples
The number of pixel samples used in the analysis
Lack of Fit (%PCA)
The fitting residue compared to the data filtered by principal
component analysis.
Lack of Fit (% EXP)
The fitting residue compared to the experimental data.
Divergence Counter
The number of divergences that occurred.
Maximum Iterations
The maximum number of iterations allowed.
Denoise (PCA)
Indicates how much of the data was filtered by principal component
analysis.
Normalization
The normalization method used in the analysis.
Non-negativity
Method
The non-negativity method used in the analysis.
Weighting Mode
The weighting method applied to the data.
Column Weighting
Mode
Indicates if column-wise weighting was used.
Row Weighting
Mode
Indicates if row-wise weighting was used.
Click to display the spectrum plot tab.
Click to display the concentration plot tab.
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9. Spectral Unmixing
9.4 Spectral Unmixing Options
In the spectral unmixing tools, the Options tab shows the user-modifiable parameters
in the spectral unmixing algorithm (Figure 9.3). It is recommended that you first perform
spectral unmixing using the default settings. Then, if necessary, change the option
settings and reanalyze the data.
Figure 9.3 Tool palette, spectral unmixing options
Table 9.3 Spectral unmixing options
134
Option
Description
Constraints
The constraints for unmixing the components.
Init
The method for generating the initial guess of the spectrum for the
selected component. “Auto” means this is automatically
determined by the software. Alternatively, you can used a loaded
spectrum as the initial guess.
Lock
The lock option determines whether the spectrum is allowed to
change. If this option is chosen, the spectrum of that component is
not updated during unmixing.
Unimod
Choose this option to apply the unimodality constraint. Unimodality
forces the spectrum to have only one peak (one extremum).
however, small magnitude extrema are allowed if they are less than
the Unimod Tolerance value. This tolerance value limits the rising
slope of the second spectral peak. For example, 5% tolerance
means that the increase in magnitude of the neighboring nodes
cannot exceed 5%.
Living Image® Software User’s Manual
Table 9.3 Spectral unmixing options (continued)
Option
Description
HP
Sets a high pass filter for the spectrum. Signal below the HP cut-off
frequency is forced to zero. Choose N/A to turn off the high pass
filter. Otherwise, the value represents the high pass cut-off
frequency. This constraint can help isolate components that are
physically mixed and difficult to distinguish.
LP
Sets a low pass filter for the spectrum Signal above the LP cut-off
frequency is forced to zero. Choose N/A to turn off the low pass
filter. Otherwise, the value represents the cut-off frequency of the
low pass cut-off frequency. This constraint can help isolate
components that are physically mixed and difficult to distinguish.
Sort
Choose this option to automatically sort the unmixed spectra in
ascending order of their center wavelength.
Force
Choose this option to force the first component to non-zero
throughout the image.
Denoise by PCA
Determines how much of the data will be filtered by principal
component analysis. Stronger denoising means less principal
components will be used in the data and more details will be lost.
Stronger denoising also may slow down the unmixing.
Unimod Tolerance (%)
The threshold for the unimodality constraint. It is the percentage of
overshoot allowed for the second spectral peak.
PCA
Mode
PCA can be performed on the original data, the correlation matrix of
the original data, or the covariance matrix of the original data.
Click to display the explained variance.
Click to display the biplot graph.
135
9. Spectral Unmixing
PCA Biplot
The PCA biplot is a visualization tool for principal component analysis. It shows a
simultaneous display of n observations (pixels) and p variables (wavelengths) on a twodimensional diagram.
PCA
Figure 9.4 PCA biplot
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Living Image® Software User’s Manual
PCA Explained
Variance
The PCA Explained Variance histogram shows the part of variance (y-axis) that can be
explained by a number of principal components (x-axis).
Figure 9.5 PCA explained variance
137
9. Spectral Unmixing
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Living Image® Software User’s Manual
10 Generating a Surface Topography
Generate the Surface Topography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
Managing Surfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142
A surface topography (surface) is a reconstruction of the animal surface derived from
structured light images. (For additional details on the surface topography, see page 247.)
A surface is required for point source fitting and 3D reconstruction of bioluminescent
sources (DLIT analysis) or fluorescent sources (FLIT analysis) inside a subject.
10.1 Generate the Surface Topography
1. Load the image sequence that you want to
analyze. (For details on how to load a sequence,
see page 45).
2. In the tool palette, click Surface Topography.
3. Click Reconstruct.
- The tomography analysis box appears (Figure
10.1).
Crop
box
Mask (purple)
Figure 10.1 Tomography analysis box
4. Draw a crop box that includes a one cm margin around the subject, if possible.
139
10. Generating a Surface Topography
5. Click Next to display the mask.
The mask is a purple overlay on the subject image that defines the area of interest
for the surface topography reconstruction. The mask should match the underlying
photograph of the subject as closely as possible without including any area outside
the subject image.
6. If you want to smooth the surface, confirm the default surface generation options
and surface smoothing parameters or enter new values. (For more details on the
parameters, see Table 10.1).
7. If you want to save the results, confirm the default name for the results or enter a
new name.
8. If necessary, adjust the threshold value so that the mask fits the subject image as
closely as possible without including any area outside of the subject. To change the
threshold, do one of the following:
• Press the left or right arrow keys on the keyboard.
• Move the Threshold slider left or right.
• Click the
arrows or enter a new value in the box.
9. Click Finish.
- The surface and 3D tools appear. For more details on the tools, see page 164.
Surface
f
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Living Image® Software User’s Manual
Table 10.1 Surface topography options & parameters
Item
Description
Surface Reconstruction
Structured Light
A drop-down list of structured light images in the
sequence. Select one for use in reconstructing the
surface.
SL Binning
The binning level applied to the pixels that are used to
construct the surface topography from the structured light
image. If Auto is chosen, the software automatically
determines the appropriate binning level. The higher the
binning level, the lower the mesh resolution. For more
details on binning, see page 206.
Reconstruct
Click to generate the surface.
Surface Smoothing
Smoothing Level
The amount of smoothing to apply to a reconstructed
surface.
Restore
Removes smoothing that was applied to a surface.
Loss Recovery
Smoothing can cause loss in the surface volume or
height. Make a selection from the drop-down list to
reduce losses. 'Height' is recommended for IVIS 200 or
IVIS Spectrum surfaces.
Smooth
Initiates the smoothing specified.
Save Results
Name
The name of the surface.
Delete
Click to delete the surface selected from the Name dropdown list.
Load
Click to load the surface selected from the Name dropdown list.
Save
Click to save the surface to the name entered in the Name
drop-down list.
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10. Generating a Surface Topography
10.2 Managing Surfaces
The generated surface can be saved for shared use by the Point Source Fitting, DLIT,
or FLIT tools.
Surface name
Figure 10.2 Tool palette, Surface topography tools
Saving a Surface
1. Confirm the default name or enter a new name.
2. Click Save.
Loading a Surface
1. Select the surface that you want to use (for point source fitting, DLIT analysis, or
FLIT analysis) from the Name drop-down list.
2. Click Load.
Deleting a Surface
1. Select the surface that you want to delete from the Name drop-down list.
2. Click Delete.
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11 Point Source Fitting
Displaying the Point Source Fitting Tools .
Point Source Fitting . . . . . . . . . . . . . .
Checking the Point Source Fitting Results .
Exporting Results . . . . . . . . . . . . . . .
Managing Point Source Fitting Results . .
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143
146
148
148
149
The point source fitting algorithm is a tool for advanced users that can be used to
estimate the optical properties of tissue, the location and power of a point source, or the
fluorescent yield of fluorophores. The software analyzes the images in a sequence
acquired in one of the following imaging modes:
• Bioluminescence
• Transillumination fluorescence (bottom-illuminated fluorescence)
• Epi-illumination fluorescence (top-illuminated fluorescence)
• Transmission
NOTE
The point source fitting algorithm requires an image sequence that includes one or
more images and a structured light image.
11.1 Displaying the Point Source Fitting Tools
The default tool palette does not include the point source fitting tools.
To display the point source fitting tools in the tool palette:
1. Select Edit →Preferences on the menu bar.
2. In the dialog box that appears, put a check mark next to Show Advanced Options, and
click OK.
- The point source fitting tools appear in the tool palette (Figure 11.1).
143
11. Point Source Fitting
Analyze tab
Params tab
Analysis tab shows the
active image sequence.
Starting parameter values.
Click the + sign to display
the position of the bottom
illumination source read
from the click info (x,y or
x,y,z, depending on the
image model).
Properties tab
Select other starting
values for the optical
properties here.
Results tab
Point source fitting results.
Figure 11.1 Tool palette, point source fitting tools & results
If the image sequence does not include a structure light image, the point source fiting tools
do not appear in the tool palette.
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Living Image® Software User’s Manual
Table 11.1 Tool palette, point source fitting
Item
Description
Analysis Tab
Image #
Image number in the active sequence.
ExWL
Excitation wavelength
EmWL
Emission wavelength
MinRadiance
Minimum surface radiance used for model fitting.
x,y
x- and y-coordinates of the bottom illumination source.
Params Tab
Model Type
The image acquisition mode.
Angle Limit (deg)
The angle limit refers to the angle between the object surface
normal and the optical axis. (For more details, see page 253.)
Spatial Filter
Filters out the noisy data at the mouse edges. A setting of 0.1
means that the analysis includes 90% of the data from the
center of mass to the edges.
Parameter starting values Note: Selecting a tissue Properties tab automatically updates
MuaEm, MusEm/ MuaEx, and MusEx in the Params tab.
x, y, or z
Source coordinates.
F-yield/Power
Fluorescence yield/strength of illumination or bioluminescence
source.
MuaEm
Absorption coefficient at the emission wavelength.
MusEm
Reduced scattering coefficient at the emission wavelength.
MuaEx
Absorption coefficient at the excitation wavelength.
MusEx
Reduced scattering coefficient at the excitation wavelength.
Restore Defaults
Resets the model type, algorithm starting parameters and
algorithm options to the default values.
Mask
A drop-down list of ROIs in the selected image. Select an ROI
to compute only the source in the ROI.
Statistics Weighting
Choose this option to apply a statistical weighting technique to
help reduce the error associated with high radiance
measurements.
LM Fitting
Click to begin the point source fitting.
Properties Tab
Tissue Properties
Make a selection from this drop-down list to specify starting
values for the parameters other than the defaults. Note:
Selecting a tissue property automatically updates MuaEm,
MusEm/ MuaEx, and MusEx in the Params tab.
Internal medium index of
refraction
The internal medium index of the tissue selected from the
Tissue Properties drop-down list. You can also enter a userspecified value.
Results Tab
MuaEm
Absorption coefficient at the emission wavelength.
MusEx
Reduced scattering coefficient at the excitation wavelength.
Mueff
Effective attenuation coefficient
Mueff =
Diff
3Mua ( Mua + Mus )
Diffusion coefficient, Diff = (Mua +Mus)/3
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11. Point Source Fitting
Table 11.1 Tool palette, point source fitting (continued)
Item
Description
X location of the source
X-coordinate of the source location.
Y location of the source
Y-coordinate of the source location.
Z location of the source
Z-coordinate of the source location.
Starting ChiSqure
Error between the measured and simulated photon density at
the start of the analysis.
Ending ChiSqure
Error between the measured and simulated photon density at
the end of the analysis.
11.2 Point Source Fitting
Point source fitting is performed separately on each image in a sequence.
1. Open the image sequence that you want to analyze.
2. In the Analysis tab, select an image in the sequence.
3. In Surface Topography tools, generate or load a surface. For more details on generating
the surface, see page 139.
Note: It is recommended that you use the smoothing tool to generate a good
quality surface.
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Living Image® Software User’s Manual
4. Click the Params tab.
- The default starting values for the source location, power, and tissue optical
properties are displayed.
Note: The software automatically selects the correct model type for the image data.
5. If you want to fix a parameter starting value, click the unlocked icon
becomes a closed lock .
so that it
6. If you want to construct the source only in a region of interest, make a selection from
the Mask drop-down list.
7. Confirm the angle limit and spatial filter defaults or enter new values.
8. To specify different starting values for the optical properties:
a. Click the Properties tab.
b. Make a selection from the Tissue Properties drop-down list.
c. Confirm the internal medium index of refraction or enter a new value.
9. In the Params tab, click LM Fitting.
- The source appears on the mesh and the Results tab displays the point source
fitting results.
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11. Point Source Fitting
11.3 Checking the Point Source Fitting Results
1. In the Results tab, click
Photon Density Maps.
- The Photon Density Maps
window appears.
2. Select the image from
the Image sources
drop-down list.
3. Compare the simulated
and measured photon
densities.
11.4 Exporting Results
To export all results:
1. In the Results tab, click Export results.
2. In the dialog box that appears, select the
destination folder for the results and click OK.
- The results include a .txt, .csv, .xsc (source
information), and a .xmh (surface mesh) file.
To export user-selected results:
1. Right-click the item of interest in the results list, and
select Export Results on the shortcut menu.
2. In the dialog box that appears, choose a folder for
the results, enter a file name (.txt), and click Save.
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Living Image® Software User’s Manual
11.5 Managing Point Source Fitting Results
To save results:
1. Select the results of interest (LMFIT_xx) from
the Name drop-down list
2. Click Save.
- The point source fitting results are saved with
the image.
To view results:
1. Select the results of interest from the Name
drop-down list.
2. Click Load.
To delete results:
1. Select the results that you want to delete from
the Name drop-down list.
2. Click Delete.
To copy selected results:
1. Right-click the results (row) of interest and select Copy Selected from the
shortcut menu that appears.
- The selected results are copied to the system clipboard.
To copy all results:
1. In the Results tab, right-click the results table and select Copy All from the
shortcut menu that appears.
- All of the results table is copied to the system clipboard.
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11. Point Source Fitting
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Living Image® Software User’s Manual
12 3D Reconstruction of Sources
3D Reconstruction of Bioluminescent Sources .
3D Reconstruction of Fluorescent Sources . . .
DLIT & FLIT Results . . . . . . . . . . . . . . . . .
3D Tools . . . . . . . . . . . . . . . . . . . . . . .
3D Tools - Mesh Tab . . . . . . . . . . . . . . . .
3D Tools - Volume Tab . . . . . . . . . . . . . . .
3D Tools - Organs Tab . . . . . . . . . . . . . . .
3D Tools - Animation Tab . . . . . . . . . . . . .
Managing DLIT/FLIT Results . . . . . . . . . . .
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152
156
158
164
170
172
175
182
187
The Living Image® software includes algorithms for 3D reconstruction of
bioluminescent or fluorescent sources (tomographic analysis):
• Diffuse Tomography (DLIT™) algorithm - For tomographic analysis of
bioluminescent sources. Analyzes a bioluminescent image sequence obtained on
the IVIS® Imaging System 200 or IVIS Spectrum.
• Fluorescent Tomography (FLIT™) algorithm - For tomographic analysis of ®
fluorescent sources. Analyzes a fluorescent image sequence obtained on the IVIS
Spectrum imaging system.
The steps to perform 3D reconstruction of bioluminescent/fluorescent sources include:
1. Acquire an image sequence.
2. Generate the surface topography (surface) of the subject.
3. Set the user-modifiable DLIT/FLIT algorithm parameters (for example, analysis
wavelengths, source spectrum, and tissue properties) and reconstruct the position,
geometry, and strength of the luminescent sources.
For more details on the DLIT/FLIT algorithm, see Appendix H, page 247.
151
12. 3D Reconstruction of Sources
12.1 3D Reconstruction of Bioluminescent Sources
General
Considerations
Animal Requirements
The best surface topography reconstruction is obtained from nude mice. It is possible
to perform 3D imaging on white or light-colored furred mice if the fur is reasonably
smooth over the mouse surface. Therefore it is recommended that you comb the fur
before imaging to eliminate any "fluffy" areas that may trigger artifacts during the
surface topography reconstruction. 3D reconstructions are currently not possible on
black or dark-colored furred mice. In this case, it is recommended that you shave the
animals or apply a depilatory.
Luminescent Exposure vs. Luciferin Kinetic Profile
It is important to consider the luciferin kinetic profile when you plan the image
sequence acquisition. The DLIT algorithm currently assumes a flat luciferin kinetic
profile. Therefore, to optimize the signal for DLIT 3D reconstruction, carefully plan the
start and finish of image acquisition and ration the exposure time at each emission filter
so that the sequence is acquired during the flattest region of the luciferin kinetic profile.
Generate a Surface
Topography
For details on generating the surface, see page 139
Set Up & Acquire an
Image Sequence
Use the imaging wizard to setup the image sequence required for DLIT™ analysis. (For
more details on the imaging wizard, see page 25.) If you plan to manually set up the
sequence, Table 12.1 shows the recommended image sequence. Analyzing more
images usually produces more accurate results. At a minimum, the sequence must
include data from at least two different emission filters (560-660 nm):
• Emission filter #1: Photographic, luminescent, and structured light image.
• Emission filter #2: Luminescent image.
Table 12.1 Recommended image sequence for DLIT analysis
Image Type
Emission Filter Options
560
Photographic
✓
Structured light
✓
Luminescent
✓
580
600
620
640
660
Select the Reuse Photographs
option in the control panel.
✓
✓
✓
✓
✓
NOTE
The binning level must be the same for all of the luminescent images.
After the surface is generated, the 3D reconstruction of the light sources can proceed.
Figure 12.1 shows example results. For more information on the DLIT algorithm and
user-modifiable parameters, see Appendix H, page 247.
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Living Image® Software User’s Manual
1. In the tool palette, click DLIT 3D Reconstruction.
2. In the Properties tab, make a selection from the
“Tissue Properties” and “Source Spectrum”
drop-down lists.
“Muscle” is usually the best choice of tissue
properties for general in vivo reconstructions.
Note: The internal medium index of refraction is
automatically entered when you select a tissue.
3. If you want to view the “Tissue Properties” (μa,
μeff, μ’s) or “Source Spectrum” for the tissue and
light source selected above, make a selection
from the Plot drop-down list in the Properties
tab.
4. In the Analyze tab, select the acquisition
wavelengths (560-660 nm).
5. If necessary, edit the minimum radiance
associated with an acquisition wavelength or
angle. For more details on the minimum
radiance, see page 253.
Note: It is recommended that you only analyze
images that have signal well above the noise.
6. To edit the minimum radiance, double-click the
entry and enter a new value.
Note: The minimum radiance level can be
observed by looking at individual images and
adjusting the min level on the color bar, in
radiance units (photons/sec/cm2).
153
12. 3D Reconstruction of Sources
7. In the Params tab, confirm the parameter defaults or enter new values.
For more details on the parameters, see Appendix H, page 247.
Angle limit default is 70° for
IVIS® Imaging System 200
Series or IVIS® Spectrum data.
DLIT algorithm
user-modifiable
parameters
Params tab
8. In the Analyze tab, click Reconstruct.
The reconstruction requires about 1-5 minutes, depending on the parameter
settings and the processor speed.
Figure 12.1 shows example 3D reconstruction results.
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Living Image® Software User’s Manual
The 3D View in the
image window
displays the surface,
the 3D reconstruction
of the bioluminescent
light sources inside
the subject (voxels),
and the photon
density map (photons/
mm3 just below the
surface).
Results tab displays the
results data and the DLIT
parameter values.
Image window, 3D view
To best view the light
sources (voxels):
1. In the 3D tools,
move the slider or
enter an opacity
value to adjust the
surface opacity.
2. Clear the Render
Photon Density
Map option to
display the surface
without the photon
density map.
Light sources (voxels)
Figure 12.1 Viewing DLIT 3D reconstruction results, Results tab (top) and 3D tools (bottom)
155
12. 3D Reconstruction of Sources
12.2 3D Reconstruction of Fluorescent Sources
Set Up & Acquire an
Image Sequence on the
IVIS® Spectrum
Use the imaging wizard to setup the image sequence required for FLIT™ analysis. (For
more details on the imaging wizard, see page 25.) If you plan to manually set up the
sequence, Table 12.2 shows the recommended image sequence. Acquire the images
using transillumination on the IVIS Spectrum using the same excitation and emission
filters from at least four source locations.
Table 12.2 Example image sequence for FLIT analysis
Image Type
Source Location
First location
Subsequent locations
Photographic
✓
Use previous photo
Structured light
✓
Fluorescent
✓
✓
Generate the Surface
Topography
For instructions, see page 151.
Set the FLIT
Parameters &
Reconstruct the
Sources
After the surface is generated, the 3D reconstruction of the light sources can proceed.
1. In the tool palette, click FLIT 3D Reconstruction.
Analyze tab
Source 01 corresponds to the first
image of the sequence, source 02
corresponds to the second image,
and so on
2. In the Properties tab, make a selection from the Tissue Properties drop-down list.
“Muscle” is usually the best choice of tissue properties for general in vivo
reconstructions.
Note: The internal medium index of refraction is automatically entered when you
select a tissue.
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Living Image® Software User’s Manual
Parameters tab
Properties tab
3. In the Params tab, confirm the parameter defaults or enter new values.
For more details on the parameters, see Appendix H, page 247. It is recommended
that you start with the default parameter settings. If necessary, fine tune the
settings in the parameters tab.
4. In the Analyze tab, select the source locations to include in the analysis and click
Reconstruct.
- Figure 12.1, page 155 shows example 3D reconstruction results
157
12. 3D Reconstruction of Sources
12.3 DLIT & FLIT Results
The Results tab displays information about the photon density, voxels, and DLIT or
FLIT algorithm parameters.
Figure 12.2 3D reconstruction results, FLIT (left) and DLIT (right)
NOTE
For more details on the DLIT and FLIT algorithm parameters, see Appendix H,
page 247. Sometimes adjusting the DLIT algorithm parameters improves the fit of the
simulated photon density to the measured photon density data.
Table 12.3 3D reconstruction results
Item
Description
Optimized fit parameters
Total source flux (phot/s) (DLIT
result)
The sum of the bioluminescent source intensities.
Total fluorescence yield (N mm2)
(FLIT result)
The total sum of the fluorescent yield. The quantity
measured is:
(Fluorescence quantum efficiency for the excitation
wavelength to emission wavelength photons)*(Excitation
wavelength photon absorption cross section)*(Fluorophore
number density)*(Volume of voxel size). To convert the
'Fluorescence Yield' measurement to the number of
fluorescent compounds, divide the 'Fluorescent Yield'
values by measured quantities of [Fluorescence quantum
efficiency of excitation wavelength conversion to emission
wavelength]*[Excitation photon absorption cross section]
for the fluorophore.
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Table 12.3 3D reconstruction results (continued)
Item
Description
Final vsize
The voxel size (length of a side, mm) that produces the
optimum solution to the DLIT or FLIT analysis.
Number of sources
The number of voxels that describe the light source(s).
Reduced Chi2
A measure of the difference between the computed and
measured photon density maps at the optimum solution. A
smaller χ2 value indicates a better quality of fit.
Starting vsize
The voxel size at the start of the analysis.
Kappa (best) (DLIT result)
The kappa value that produces the optimum solution.
N surf (best)
The number of surface element data analyzed per
wavelengths/images.
Total surf samples
The total number of surface element data analyzed for all
wavelengths/images.
Threshold angle
The angle that the object surface normal makes with the
optical axis. The optical axis can be considered to be a line
perpendicular to the stage. The default setting for this limit
is 70° for IVIS Spectrum or IVIS 200 data. For more details,
see Angle Limit, page 253.
Kappa limits (DLIT result)
The kappa parameter is a parameter that is searched during
a reconstruction to determine the best fit to the image data.
For more details, see Kappa Limits (DLIT), page 254.
N surface limits (DLIT result)
The maximum number of surface intensity points to use in
the reconstruction for each wavelength. The range is 200 to
800 and the default is 200. The reconstruction time is
shorter for smaller values of N (for example, 200). However
larger values of N may give a more accurate result because
more data are included in the fit.
Starting Voxel Size (DLIT/FLIT)
The length of the side of the voxel cube in mm units for the
coarsest initial grid size in the adaptive gridding scheme.
Voxel size limits (DLIT result)
The starting voxel size range evaluated by the algorithm to
determine the optimum solution.
Voxel size increment (DLIT result) The incremental change in voxel size evaluated at each
iteration during the DLIT analysis.
Uniform Surface Sampling
TRUE = the option is chosen and the surface data for each
wavelength is sampled spatially uniformly on the signal
area. FALSE = the option is not chosen and the N brighter
surface elements are used as data in the reconstruction.
NNLS + Simplex Optimization
TRUE = the option is chosen and a non-negative least
squares optimization algorithm is used in addition to the
SIMPLEX algorithm to seek the optimum solution. FALSE
= only the NNLS algorithm is used to seek the optimum
solution.
NNLS Weighted Fit
TRUE = the option is chosen and the DLIT or FLIT algorithm
weights the wavelength data inversely proportional to its
intensity in the NNLS reconstruction. FALSE = the option is
not chosen
Min Radiance
The wavelength image data minimum radiance [photons/
sec/cm2/sec] to use in the DLIT or FLIT analysis.
Index of Refraction
The internal medium index of refraction that is associated
with the user-selected tissue.
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12. 3D Reconstruction of Sources
Table 12.3 3D reconstruction results (continued)
Item
Description
Tissue Properties
The user-specified tissue in which the sources should be
located.
Source Spectrum
The emission spectrum of the type of bioluminescent
source.
Photon Density Maps
Simulated
The photon density computed from DLIT/FLIT source
solutions which best fit the measured photon density (see
page 161).
Measured
The photon density determined from the image
measurements of surface radiance.
Wavelength
The wavelength of the photon density map in the active
image.
Source Image
The image number of the transillumination source image.
Photon Density Maps
Click to open the Photon Density Maps window.
Save Results
Viewing Photon
Density
Name
The default name for the active DLIT or FLIT results.
Delete
Click to delete the selected DLIT or FLIT results.
Load
Click to load the selected DLIT or FLIT results.
Save
Click to save the active DLIT or FLIT results.
Overwrite
If you reanalyze saved results, click to save the new results
and overwrite the previous results.
Photon density is the steady state measure of the number of photons in a cubic
millimeter. Light sources inside the tissue contribute to photon density in other portions
of the tissue. The DLIT or FLIT algorithm first converts the luminescent image of
surface radiance to photon density just below the animal surface because this is what
can be observed. Then the DLIT or FLIT algorithm solves for point source locations
inside the tissue which would produce the observed photon density near the surface.
To check the quality of the DLIT or FLIT construction, it is useful to compare the
measured and simulated photon density plots. The photon density is closely related to
the measured radiance.
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To view the photon density maps:
1. In the Results tab, click Photon Density Maps.
- The Photon Density Maps window displays the photon density maps for all
wavelengths.
Select one or all wavelengths for display.
Move the wheel
to the left or right
to rotate the
surface on the
vertical axis.
Note: The voxels are also automatically displayed when the 3D reconstruction is
completed. For more details on measuring the voxels, see page 172.
2. To display the measured and simulated photon density profiles:
a. Select a wavelength.
b. Drag the crosshair to the location of interest.
- The horizontal and vertical photon density profiles are updated.
In a good reconstruction, the
measured (blue) and
simulated (red) photon
density curves are close.
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3D Tools
The 3D tools appear in the tool palette when a surface topography (surface) or 3D
source is reconstructed, or when you open saved results.
For Details on...
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See Page
3D tool buttons
164
Mesh tab
170
Volume tab
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For Details on...
See Page
Organs tab
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Animation tab
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12. 3D Reconstruction of Sources
12.4 3D Tools
Click:
to select a tool to work with the surface or 3D results (perspective view only).
to select a surface drawing style.
to select a shading style for the surface.
Figure 12.3 3D tools and DLIT results in the 3D view window
Table 12.4 3D Tools
Item
Description
Image Tools
A drop-down list of tools for viewing and working with the surface or DLIT
results.
Select
to:
• Click and display measurement dimensions in the coronal, sagittal, or
transaxial view (in the 3D view window).
• Drag a measurement cursor in the coronal, sagittal, or transaxial view and
display measurement dimensions. (For details on measurement cursors,
see page 173.)
Select
to zoom in or out on the image (use a click-and-drag operation).
Select
to move the subject in the window (use a click-and-drag
operation).
Select
to rotate the subject around the x, y, or z axis (use a click-anddrag operation).
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Table 12.4 3D Tools
Item
Drawing Styles
Description
A drop-down list of drawing styles for the surface (for examples, see
) is the
default.
Figure 12.3, page 164). The Surface face drawing style (
Point cloud
Wire frame
Surface face
Wire frame and surface face
Shading Styles
A drop-down list of shading styles for the surface (for examples, see ,
page 166). The Reflect smooth surface face shading style ( ) is the
default.
Smooth face
Smooth surface face
Reflect surface face
Reflect smooth surface face
Select this tool from the drop-down list to change the view perspective
(top, bottom, left, right, front, back, or perspective view). For examples of
the views, see Figure 12.6.
Select this tool from the drop-down list to display the perspective view.
Click to show or hide measurement cursors in the coronal, sagittal, or
transaxial views.
Click to display the manual transform tool.
Automatic atlas registration tool.
Click a voxel in the 3D reconstruction, then click this button to display
measurements for the voxel in the 3D tools (source voxel measurements).
Click to hide or show the x,y,z-axis display in the 3D view window.
Click to hide or show coronal, sagittal, and transaxial planes through the
subject in the 3D view window.
Click to show or hide a bounding box around the subject.
Click to show or hide a grid under the subject.
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12. 3D Reconstruction of Sources
Rotate, Move, or Zoom
on a 3D Image
Select a tool from the drop-down list.
Axis shows image orientation.
To rotate the image:
1. Choose the
or
tool.
2. Place the pointer in the 3D View window.
3. Click and drag the pointer in the x, y, or z-axis direction.
- The x,y,z-axis shows the orientation of the image.
To move the image:
1. Select the
arrow in the 3D tools and drag the image. Alternatively, press the
Shift key while you drag the image.
To zoom in or out on the image:
1. Select the
arrow in the 3D tools.
2. To zoom in on the image (magnify), right-click (Ctrl+click for Macintosh users) and
drag the
toward the bottom of the window.
To zoom out on the image, right-click and drag the
toward the top of the window.
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Selecting a Drawing or
Lighting Style for the
Surface
You can choose a different drawing and lighting style to change the appearance of the
surface.
To choose a drawing style, make a selection from the Drawing style drop-down list in the 3D
tools.
Point cloud surface
Wire frame surface
Surface face surface
Wire frame &
surface face
Figure 12.4 Surface drawing styles
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12. 3D Reconstruction of Sources
To choose a shading style, make a selection from the Shading style drop-down list in the 3D tools.
Surface face
Smooth surface face
Figure 12.5 Surface shading styles
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Reflect surface face
Reflect smooth
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Changing the View
Perspective
You can view a 3D image from different perspectives. Figure 12.6 shows examples of
the other available views.
To change the view:
• Select
to change the view.
• Alternatively, click the surface, then press the V key to cycle through the different
views of the surface (Figure 12.6).
•Select
to display the perspective view.
Note: Only the perspective view (the default view) can be rotated or moved in the 3D
view window.
View name
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Top
Bottom
Front
Back
Left
Right
Figure 12.6 Alternative views of the surface
12.5 3D Tools - Mesh Tab
The Mesh tab includes tools for viewing the reconstructed surface, photon density
maps, and planes through the 3D reconstruction.
Figure 12.7 3D tools, mesh tab
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Table 12.5 Mesh tab
Item
Description
Render Mesh
Choose this option to display the surface in the 3D view window. It may be
helpful to turn off the surface to better view the photon source 3D
reconstruction.
Opacity
Controls the surface opacity. A lower number makes the surface more
transparent. This may be helpful for viewing the photon source 3D
reconstruction.
Photon Density
Map
Choose this option to display the photon density map. (If the DLIT
reconstruction of the bioluminescent source has not been generated, this
option is not available.)
Apply
Select the simulated (computed by the DLIT algorithm) or measured photon
density for the photon density map.
Images
A drop-down list of the images used to reconstruct the surface. Make a
selection from the list to view the DLIT/FLIT results associated with a
particular image.
Threshold
Intensity
Color Table
Choose this option to apply a photon density threshold (photons/mm3) to
the photon density map.
Use the Intensity slider, the arrows or enter a value in the box to set the
minimum intensity threshold.
Specifies the color table for the source intensity scale.
Reverse
Choose this option to reverse the color table. For example, the BlackRed
color table represents the source intensity (photons/sec) from low to high
using a color scale from black to red. If Reverse is chosen, the source
intensity (photons/sec) from low to high is represented using the color scale
from red to black.
Logarithmic
Scale
Choose this option to apply a logarithmic scale to the color table.
Slice
Move a slider to change the position of the coronal, sagittal, or transaxial
plane through the surface. The intersection of the plane and subject (slice)
is shown in the coronal, sagittal, and transaxial views in the 3D view
window.
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12.6 3D Tools - Volume Tab
The voxels are automatically displayed when the 3D reconstruction is complete. In the
3D tools, the Volume tab displays the voxel intensity and other data, and provides tools
for voxel measurement and display.
Figure 12.8 3D tools, Volume tab
Table 12.6 3D tools, Volume tab
Item
Description
Render Volume
Choose this option to display the voxels.
Min
The minimum voxel intensity (photons/sec for DLIT results; N mm2 for
FLIT results).
Max
The maximum voxel intensity (photons/sec).
Render voxels as A drop-down list of shapes for voxel display.
Threshold
Intensity
Color Table
Reverse
Choose this option to apply a minimum threshold intensity to the voxel
display.
Use the Intensity slider, the
arrows, or enter a value in the box to
set the minimum threshold intensity.
Specifies the color table for the voxel intensity scale.
Choose this option to reverse the color table. For example, the
BlackRed color table represents the source intensity (photons/sec)
from low to high using a color scale from black to red. If Reverse is
chosen, the source intensity (photons/sec) from low to high is
represented using the color scale from red to black.
Logarithmic Scale Choose this option to apply a logarithmic scale to the color table.
Source Voxel
Measurement
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Click the
button, then click a voxel in the 3D reconstruction to
display measurements for the voxel.
Total Flux (DLIT
results)
The total flux measured for the voxels selected using the voxel tool.
Total
Fluorescence
Yield
(FLIT results)
N mm2 measured for the voxels selected using the Measure Voxels
tool
.
Volume
Volume of the selected voxels (mm3).
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Table 12.6 3D tools, Volume tab (continued)
Item
Description
Center of mass
The weighted average x, y, and z-coordinates of the selected voxels,
where the weights are the flux of each highlighted voxel.
Host Organ
Organ location of the selected voxel(s).
Center of Mass
Click to compute the center of mass for the selected voxel(s).
Export Voxels
Enables you to export the voxel measurements (.csv).
To display voxel measurements:
1. Click the Measure Voxels button
.
2. On the surface, click a voxel. Alternately, draw a box around a group of voxels.
- The Voxel tab displays the selected voxel data.
Voxel
data
Coronal, sagittal, & transaxial views
Figure 12.9 Example 3D reconstruction, FLIT results
3. Repeat step 2 to display data for other voxels.
- The voxel data is updated.
4. To clear the voxel data, click any where in the 3D view window.
To measure the depth of a source(s):
1. Click the Measure Voxels button
.
2. Click a voxel or draw a box around a group of voxels.
3. Click Center of Mass.
The Coronal, Sagittal and Transaxial views display the intersection through the
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12. 3D Reconstruction of Sources
voxels' center of mass.
4. Click the Measurement Cursor button
.
- The Sagittal and Transaxial views show the distance between the voxel(s) and the
dorsal or ventral surface (Figure 12.9).
5. To measure another distance, drag each end of the measurement cursor (
a new position.
) to
- The distance measurement is updated.
Viewing X,Y
Coordinates
1. In the Coronal, Sagittal, or Transaxial
windowpane, click the position of
interest.
- The x,y-coordinates (mm) of the
position are displayed.
2. If you drag the mouse cursor, the
coordinates are updated.
To display planes in the 3D image:
1. Click a voxel
2. Click the
button.
- The Coronal, Sagittal, and Transaxial view shows the plane (slice) through the
voxel.
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Sagittal plane
Transaxial plane
Coronal
plane
Coronal, sagittal, and transaxial views show the slice
through the surface taken by the associated plane.
3. To change the location of a plane, move the coronal, sagittal, or transaxial slider left
or right. Alternatively, click the slider, then press the ←or →keyboard arrow keys.
- The Coronal, Sagittal, or Transaxial windowpane is automatically updated.
12.7 3D Tools - Organs Tab
The Living Image® software provides digital mouse atlases that enable you to display a
3D skeleton and organs on the 3D reconstruction (Table 12.7). Select the atlas and organs
that you want to display in the Organs tab. The software automatically aligns the organs
on the surface. However, you can also manually adjust the scale or location of organs
on the surface. You can also import a custom organ atlas created from Open Inventor
files (.iv).
Figure 12.10 3D tools, Organs tab
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12. 3D Reconstruction of Sources
Table 12.7 Organ atlases
Atlas
Description
Mouse Atlas-Female Male or female in a dorsal or ventral orientation. Atlas includes organs
or Male
only, no skeleton.
CT-Female or Male
Male or female in dorsal, ventral, or lateral orientation. Atlas includes
organs and skeleton.
Table 12.8 3D tools, Organs tab
Item
Description
Organs
Choose this option to enable the selection and display of organs on the surface.
Organ
database
Choose the male or female organ database from the drop-down list.
Organs
A list of the organs in the selected organ database. Select the organ(s) that you
want to display on the surface.
Reset
Click to display the selected organs in their default positions.
Click to select all organs in the database and display them on the surface.
Click to clear the selected organs and remove all organ diagrams from the
surface.
Update scene Click to display the selected organs on the surface.
Displaying Organs
1. In the 3D Tools, click the Organs tab.
2. Confirm that the surface is in the perspective view (click the
R key).
3. Choose the Render Organs option.
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4. Select an organ atlas.
- All of the organs in the selected atlas appear on the surface.
5. To co-register the digital organs and the surface:
a. Click the Fit organs to the mouse button
.
b. On the drop-down list that appears, click a button to choose an option:
Rigid registration - Performs linear transformation, but keeps the shape of the
atlas surface.
Full registration - Performs linear transformation and volume deformation.
NOTE
For an optimum fit when there is a large difference between the orientation or size of
the atlas organs and surface, first use the transformation tool to manually register the
surface and atlas organs, then click the
or
tool to automatically fit the organs.
(For more details on manual registration, see below.)
6. If necessary, adjust the opacity of the organs using the slider or enter a number in
the box.
The organs are easier to view if you do not select Skin in the Organs list.
7. To clear all organs from the surface, click the Deselect All button
specific organ, remove the check mark next to the organ name.
. To remove a
8. To display a specific organ(s), choose the organ name. To display all organs on the
surface, click the Select All button .
NOTE
If you manually change the location, orientation, or scale of an organ(s), you can click
Reset to restore the default size and position of the selected organs.
Manually Adjusting
the Scale or Location
of Organs
1. Follow step1 to step 4 above.
2. Click the Transform tool button
.
- The transform tool appears.
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Transform tool
In this example, “Skin” is
selected from the organ list.
3. To adjust the x,y, or z-position of the organ, drag the transform tool.
4. To return the transform tool to the default location, click Reset.
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5. Press the Tab key to put the transform tool in
scale mode.
- A red cube appears at each corner of the
transform tool.
6. To increase or decrease (scale) the size of the
organ, drag a red cube at a corner of the
transform tool. Note: To restrict scaling to a
particular axis, press the X, Y, or Z key, then
drag a red cube.
7. Press the Tab key again to put the transform
tool in rotate mode.
- A red, green, and blue circle appear around
the surface.
8. To rotate the organ on the x,y, or z-axis, click
the blue, green, or red circle and drag the
mouse arrow in the direction of interest.
Note: To return the organ drawing to the
default position and size, click Reset and the
button.
9. To turn off the transform tool, click the
button.
Circle line is thicker when selected
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12. 3D Reconstruction of Sources
To check the organ and surface alignment:
1. Check the organ position in the Coronal, Sagittal, and Transaxial windowpanes.
2. In the 3D View tab, click in the
windowpane with the surface.
3. Press the V key or the
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button to display alternative views of the surface.
Top
Bottom
Front
Back
Left
Right
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Importing an Organ
Atlas
You can import an organ atlas (Open Inventor format, one organ per .iv) derived from
MRI or CT scans.
NOTE
The imported atlas must include a skin file named skin.iv.
To import an organ atlas:
1. Open the DLIT results that are associated with the organ atlas.
2. Select File →Import →Organ Atlas on the menu bar.
3. In the Import Organ Atlas box that appears, click Add Organ Files.
4. In the next dialog box that appears, select all of the Open Inventor files that you
want to include in the atlas (one .iv per organ) and click Open.
5. In the Select Skin Mesh drop-down list, select the skin organ file, which must have
the file name ‘skin.iv’.
6. Click Generate Mesh Coefficients.
7. Enter a name for the atlas and click Save Organ Atlas.
- The organ atlas (.atlas) is created. The atlas name appears in the Organ Atlas dropdown list (in the 3D tools, Organs tab).
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12.8 3D Tools - Animation Tab
The Living Image software can produce an animation from a sequence of 3D views or
key frames. For example, an animation can depict:
• Magnifying (zooming in on) the 3D view.
• Spinning the 3D view on an axis.
• The surface or organs fading out (decreasing opacity) or fading in (increasing
opacity).
The animation can be saved to a movie (.mov, .mp4, or .avi).
In the Animation Tab, You Can:
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Create a custom animation (generated from your custom animation setup)
185
Edit & save an animation setup
186
Key frame box shows the key frames
in the current animation setup
Click a key frame to display the
associated 3D view and time stamp
(position in the time scale (0-100) at
which the frame occurs in the
animation).
Figure 12.11 Animation tab
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See Page
View a preset animation (generated from a predefined animation setup)
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Table 12.9 3D tools, Animation tab
Item
Description
Time Scale%
The time stamp of a key frame in the animation on a time scale of 0-100.
For example, if the animation is 10 sec long and includes five key
frames:
Key frame 1: Time stamp= 0; first frame of the animation.
Key frame 2: Time stamp = 25%; frame occurs 2.5 seconds after the
start of animation.
Key frame 3: Time stamp = 50%; frame occurs 5.0 seconds after the
start of animation.
Key frame 4: Time stamp = 75%; frame occurs 7.5 seconds after the
start of animation.
Key frame 5: Time stamp = 100%; last frame of the animation.
Presets
A drop-down list of predefined animation setups.
Key frame
A 3D view. The software interpolates the key frames to create
intermediate frames in real time, then generates an animated sequence
from all of the frames. Each successive key frame in a sequence should
differ slightly from the preceding one, so that motion is smoothly
depicted when the frames are shown at a proper frame rate (frames/
second). The Living Image software provides preset key frames or you
can specify the 3D views for the key frames.
Preset Key Frame
Factor
Determines how many key frames are used to generate one revolution
in a spinning animation (No. of frames = (4 x Key Frame Factor) + 1).
Increasing the key frame factor reduces the time period between key
frames and creates the appearance of finer movement. Decreasing the
key frame factor increases the time period between key frames and
creates the appearance of coarser movement.
FPS
Frames displayed per second in the animation sequence.
Click to create a new key frame from the current 3D view.
Click to update the selected key frame to the current 3D view.
Click to delete a selected or all key frames from the key frame box.
Click to move a selected key frame up in the key frame box.
Click to move the selected key frame down in the key frame box.
Total Duration
The total time of the animation sequence.
Play
Click to view the animation sequence defined by the current key frames
and animation parameters.
Record
Displays a dialog box that enables you to save the current animation to
a movie (.mov, .mp4, or .avi).
Animation Setup
Load
Displays a dialog box that enables you to open an animation setup (.xml).
Save
Displays a dialog box that enables you to save the current key frames
and animation parameters to an animation setup (.xml).
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Viewing a Preset
Animation
To view a preset animation:
1. Open the DLIT/FLIT results.
2. Confirm that the 3D view shows the properties of interest (for example, organs,
voxels, surface, or photon density maps).
3. In the 3D Tools, click the Animation tab.
4. If necessary, clear the key frame box (click the
button and select Delete All).
5. To view a preset animation, make a selection from the Presets drop-down list. (See
Table 12.10 for a description of the preset animations.)
- A list of the key frames appears.
6. To view the animation, click Play.
NOTE
You can view multiple animations sequentially. For example, if you select Spin CW
on X-Axis and Spin CW on Y-axis from the Presets drop-down list, the animation
shows the 3D reconstruction spinning clockwise on the x-axis, then spinning
clockwise on the y-axis.
To save the animation to a movie:
1. Click Record.
2. In the dialog box that appears, choose a directory, enter a file name (.mov, mp4,
.avi), and click Save.
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Table 12.10 Preset animations
Creating a Custom
Animation
Name
Choose This Animation Setup to...
Spin CW
Rotate the 3D reconstruction clockwise.
Spin CCW
Rotate the 3D reconstruction counterclockwise.
Zoom In
Magnify the 3D reconstruction.
Fade In
Increase opacity from 0-100%.
Fade Out
Decrease opacity from 100-0%.
To create an animation, you must specify a custom animation setup or edit an existing
setup.
1. Open the 3D results of interest.
2. Confirm that the 3D view shows the properties of interest (for example, position or
scale of the 3D reconstruction, organs, voxels, surface, or photon density maps).
3. In the 3D tools, click the Animation tab.
4. If necessary, clear the key frame box (click the
5. To capture the first key frame, click the
button and select Delete All.)
button.
- The first key frame is added to the key frame box.
6. To capture the next key frame, adjust the 3D view to show the properties of interest
and click the
button.
- The second key frame is added to the key frame box.
7. Repeat Step 6 until all key frames of interest are captured. For details on how to edit
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the key frame sequence, see page 186.
Click a key frame to display the associated 3D view and the time stamp (position
in the time scale (0-100) at which the frame occurs in the animated sequence).
8. Confirm the defaults for FPS (frames per second) and Total Duration (length of
animation) or enter new values.
FPS x Total Duration = No. of frames generated to create the animation. The
number of generated frames should be ≥ to the number of key frames. Otherwise,
the frames may not be properly animated.
9. To view the animation, click Play. To stop the animation, click Stop.
To save the animation to a movie:
1. Click Record.
2. In the dialog box that appears, choose a directory and enter a file name (.mov, mp4,
.avi), and click Save.
To save the animation setup:
1. Click Save.
2. In the dialog box that appears, select a directory and enter a file name (.xml).
Editing an Animation
Setup
Open an animation setup:
1. To select a predefined setup, make a selection from the Preset drop-down list.
or
To select a saved user-defined setup:
a. Click Load.
b. In the dialog box that appears, select the directory and animation setup (.xml) of
interest.
To edit the key frame sequence:
1. Add a key frame:
a. Adjust the 3D view to show the properties of
interest.
b. Click the
button.
2. To reorder a key frame in the sequence, select the key
frame and click the or arrow.
3. Update a key frame:
a. Select the key frame of interest.
b. Adjust the 3D view.
c. Click the
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4. Delete a key frame:
a. Select the key frame that you want to remove.
b. Click the
button and select Delete Current.
To save the animation setup:
1. Click Save.
2. In the dialog box that appears, select a directory and enter a file name (.xml).
12.9 Managing DLIT/FLIT Results
Default name for the results
Figure 12.12 3D analysis results
To save results:
1. In the Results tab of the DLIT/FLIT 3D reconstruction tools, confirm the default file
name or enter a new name.
2. Click Save.
- The results are saved to the sequence click number folder and are available in the
Name drop-down list.
To open results:
1. In the Results tab, make a selection from the Name drop-down list.
2. Click Load.
To copy user-specified results:
1. In the Results tab, select the results of interest.
2. Right-click the results table and select Copy Selected from the shortcut menu that
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appears.
To copy all results:
1. In the Results tab, right-click the results table and select Copy All from the
shortcut menu that appears.
- All of the results table is copied to the system clipboard.
To export results:
1. In the results tab, right-click the results table and select Export Results from the
shortcut menu that appears.
2. In the dialog box that appears, choose a folder for the results, enter a file name,
and click Save.
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13 Troubleshooting Guide
13.1 DLIT/FLIT Analysis Troubleshooting
Table 13.1 DLIT/FLIT analysis
Issue
Solution
Large voxels (> 2 mm)
• The Ndata>Nvoxels is required for an overdetermined problem. It is possible that there are not
enough data (N Surface). This can occur because it is desired that all wavelengths (DLIT) and all
trans-illumination source positions (FLIT) are represented in the data equally. In the DLIT case,
if the signal in a short wavelength is very low, then the sampled data can be too few for sufficient
refinement of the voxel gridding.
– To increase the data to be included, determine the [photons/sec/cm2/sec] level for ~30 counts
on the low signal image (this is the level of noise) using Image Adjust in the Tool Palette. Enter
in the [photons/sec/cm2/sec] value into the 'Minimum Radiance' column next to the
wavelength/image number in the 'Analyze Tab' in the DLIT/FLIT 3D Reconstruction menu of
the Tool Palette.
• It is best to include the low signal data as it adds constraining information to the solution.
Note: Using the Imaging Wizard should reduce the occurrence of low signal images in the data
sequences.
No sources in solution
• In DLIT or FLIT, this can occur if the surface is not correct. That is, if a surface is imported into
the 3D View from another source other than from the Structured Light Analysis.
• In FLIT, if you choose an emission Source Spectrum in the Properties Tab (an Advanced User
feature) which is incorrect for the fluorophore of interest, this can also result in no sources.
• In FLIT, if there is very little signal detected at the surface and the 'Background' box is checked
in the Params tab, then it is possible that only the background fluorescence is simulated.
Surfaces are spiky
• The most common source of spiky surfaces are folds in the animal skin or animal fur, which
corrupt the desired smooth lines projected on the animal from the laser galvanometer.
– Adjusting the 'Path Averaging Size' in the 'Surface Topography' menu in the Tool Palette can
help reconstruct an improved surface
– Smoothing the surface by using the 'Smooth' feature in the tool palette Surface Topography
menu can also help improve the surface.
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Appendix A IVIS Acquisition Control Panel
The control panel provides the image acquisition functions (Figure A.1).
To acquire an image using auto exposure,
click the
arrow and select Auto.
Luminescence
imaging settings
Fluorescence
imaging settings
Photographic
imaging settings
Structured light
imaging settings
Figure A.1 IVIS acquisition control panel, auto exposure selected
NOTE
The options available in the IVIS acquisition control panel depend on the selected
imaging mode, the imaging system, and the filter wheel or lens option that are
installed.
Table A.1 IVIS acquisition control panel
Item
Description
Luminescent
Choose this option to acquire a luminescent image.
Fluorescent
Choose this option to acquire a fluorescent image.
Exposure time
The length of time that the shutter is open during acquisition of a photographic or luminescent image. The
luminescent or fluorescent signal level is directly proportional to the exposure time. The goal is to adjust the
exposure time to produce a signal that is well above the noise (>600 counts recommended), but less than
the CCD camera saturation of ~60,000 counts.
Luminescent exposure time is measured in seconds or minutes. The minimum calibrated exposure time is
0.5 seconds. The exposure time for fluorescent images is limited to 60 seconds to prevent saturation of the
CCD. There is no limit on the maximum exposure time for luminescent images; however, there is little
benefit to exposure times greater than five minutes.The signal is linear with respect to exposure time over
the range from 0.5 to 10 minutes. Integration times less than 0.5 seconds are not recommended due to the
finite time required to open and close the lens shutter.
Binning
Controls the pixel size on the CCD camera. Increasing the binning increases the pixel size and the sensitivity,
but reduces spatial resolution. Binning a luminescent image can significantly improve the signal-to-noise
ratio. The loss of spatial resolution at high binning is often acceptable for in vivo images where light emission
is diffuse. For more details on binning, see Appendix C, page 206.
Recommended binning: 1-4 for imaging of cells or tissue sections, 4-8 for in vivo imaging of subjects, and
8-16 for in vivo imaging of subjects with very dim sources.
191
A. IVIS Acquisition Control Panel
Table A.1 IVIS acquisition control panel (continued)
Item
Description
F/stop
Sets the size of the camera lens aperture.The aperture size controls the amount of light detected and the
depth of field. A larger f/stop number corresponds to a smaller aperture size and results in lower sensitivity
because less light is collected for the image. However, a smaller aperture usually results in better image
sharpness and depth of field.
A photographic image is taken with a small aperture (f/8 or f/16) to produce the sharpest image and a
luminescent image is taken with a large aperture (f/1) to maximize sensitivity. For more details on f/stop, see
Appendix C, page 205.
Excitation Filter
A drop-down list of fluorescence excitation filters. For fluorescent imaging, choose the appropriate filter for
your application. For bioluminescent imaging, Block is selected by default. If you select Open, no filter is
present. For systems equipped with spectral imaging capability, choose the appropriate emission filter for
your application.
Note: The excitation filter selection automatically sets the emission filter position.
Emission Filter
A drop-down list of fluorescence emission filters located in front of the CCD lens. The emission filter wheel
is equipped with filters for fluorescence or spectral imaging applications. The number of filter positions (6 to
24) depends on the system. For bioluminescent imaging, the Open position (no filter) is automatically
selected by default.
Photograph
Choose this option to automatically acquire a photographic image. The illumination lights at the top of the
imaging chamber are on during a photographic image so that the system can acquire a black and white
photograph of the sample(s).
Note: You can adjust the appearance of the photographic image using the Bright and Gamma controls (see
Image Layout Window, page 62).
Structure
Choose this option to take a structured light image (an image of parallel laser lines scanned across the
subject) when you click Acquire. The structured light image is used to reconstruct the surface topography
of the subject which is an input to the Diffuse Luminescence Imaging Tomography (DLIT™) algorithm that
computes the 3D location and brightness of luminescent sources.
When this option is chosen, the f/stop and exposure time are automatically set to defaults for the structured
light image (f/8 and 0.2 sec, respectively). The spatial resolution of the computed surface depends on the
line spacing of the structured light lines. The line spacing and binning are automatically set to the optimal
values determined by the FOV (stage position) and are not user-modifiable.
Overlay
If this option is chosen, the system automatically acquires a photographic image followed by a luminescent
image, then coregisters the two images.
Lights
Turns on the lights located at the top of the imaging chamber.
Fluor Lamp
Level
Sets the illumination intensity level of the excitation lamp used in fluorescent imaging (Off, Low, High, and
Inspect). The Low setting is approximately 18% of the High setting. Inspect turns on the illumination lamp
so that you can manually inspect the excitation lamp.
Note: Make sure that the filters of interest are selected in the filter drop-down lists before you select
Inspect. The Inspect operation automatically positions the selected filters in the system before turning on
the lamp. Subsequent changes to the filter popup menus will have no effect until another Inspect operation
is performed.
Field of View
Sets the size of the stage area to be imaged by adjusting the position of the stage and lens. The FOV is the
width of the square area (cm) to be imaged. A smaller FOV gives a higher sensitivity measurement, so it is
best to set the FOV no larger than necessary to accommodate the subject or area of interest. The FOV also
affects the depth of field (range in which the subject is in focus). A smaller FOV results in a narrower depth
of field. Select the FOV by choosing a setting from the drop-down list. For more details on the calibrated
FOV positions A-E, see Table A.3, page 194.
Service
Click to move the stage to a position for cleaning the imaging chamber below the stage. Only available on
the IVIS 200 and Spectrum imaging systems.
Load
Click to move the stage from the cleaning position back to the home position.
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Living Image® Software User’s Manual
Table A.1 IVIS acquisition control panel (continued)
Item
Description
XFOV-24
Note: This check box is only available on an IVIS® System that includes the XFO-24 lens option. When the
XFO-24 lens is installed, choose the XFOV-24 option. For more details on how to install the XFO-24 lens, see
the XFOV-24 Lens Instructions.
!
IMPORTANT
ALERT! If you remove the XFO-24 lens from the system, be sure to remove the check mark from the XFOV24 check box.
Subject height
(cm)
Sets the position of the focal plane of the lens/CCD system by adjusting the stage position. The subject
height is the distance above the stage that you are interested in imaging. For example, to image a mouse
leg joint, set the subject height to a few mm. To image the uppermost dorsal side of a mouse, set the subject
height to the 1.5 - 2.0 cm. The default subject height is 1.5 cm.
!
IMPORTANT
ALERT! The IVIS® System has a protection system to prevent instrument damage, however always pay
close attention to subject height, particularly on the IVIS Imaging System 200 Series. For example, it is
possible for a large subject (10 cm ventral-dorsal height) to contact the top of the imaging chamber if you
set the subject height = 0 and choose a small FOV.
Focus
Drop-down list of focusing methods available:
Use subject height - Choose this option to set the focal plane at the specified subject height.
Manual - Choose this option to open the Focus Image window so that you can manually adjust the stage
position. For more details on manual focusing, see page 34.
Temperature
The temperature box color indicates the temperature and status of the system:
System not initialized.
System initialized, but the CCD temperature is out of range.
System is initialized and the CCD temperature is at or within acceptable range of the demand
temperature and locked. The system is ready for imaging.
Click the temperature box to display the actual and demand temperature of the CCD and stage. For more
details, see page 11.
Acquire
Click to acquire an image using the settings and options selected in the control panel or to acquire an image
sequence specified in the Sequential Setup table.
Sequence Setup Click to display the Sequence Editor so that you can access the imaging wizard, specify and manage
sequence acquisition parameters, or open sequence acquisition parameters (xsq). For more details on
setting up an image sequence, see page 22.
Image Setup
Click to close the Sequence Editor.
Initialize
Click to initialize the IVIS Imaging System. For more details on initializing the system, see page 11.
193
A. IVIS Acquisition Control Panel
Table A.2 Additional IVIS® System Controls for the IVIS Imaging System 200 Series or IVIS Spectrum
Item
Description
Alignment grid
Choose this option to activate a laser-generated alignment grid on the stage when the imaging
chamber door is opened. The alignment grid is set to the size of the selected FOV. The grid
automatically turns off after two minutes. If subject alignment is not completed in two minutes,
place a check mark next to Enable Alignment Grid to turn on the grid.
Note: The horizontal cross hair of the alignment grid is offset appropriately to take into account the
height entered in the Subject height box.
Focus
Scan Mid Image - Choose this option in the Focus drop-down list to set the focal plane at the
maximum dorso-ventral height of the subject at the middle of the animal. This focusing method uses
the laser to scan horizontally across the middle of the subject to determine the maximum subject
height along this line. This option is well suited for animal imaging because the peak height is clearly
identified as the maximum height on the dorsal side along the mid-plane of the animal.
Note: This focusing method is not recommended for microplates or when using a high
magnification field of view (FOV A = 4.0 cm). In these situations, Manual or Subject Size focus
methods are recommended.
Transillumination Setup
(IVIS Spectrum only)
Choose this option to display the transillumination setup window that enables you to select the
locations for image acquisition using bottom illumination that originates beneath the stage.
Table A.3 Typical field of view (FOV) settings
w
IVIS® Imaging System
FOV Setting
Lumina
100 Series
200 Series
Kinetic
FOV (cm)
A
4
10
3.9
4
B
7
15
6.5
7
C
10
20
13
10
D
12
25
19.5
12
E
194
26
Living Image® Software User’s Manual
Appendix B Preferences
General Preferences
User Preferences . .
Acquisition . . . . . .
Theme . . . . . . . .
Tissue Properties . .
3D Analysis . . . . .
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196
198
199
200
201
202
You can manage user IDs and specify defaults for some parameters that are associated
with the user ID selected at the start of a new session.
1. After you log on, to view the user-modifiable preferences, select Edit
➞Preferences on the menu bar.
- The Preferences box appears.
NOTE
Any changes made to the Preferences are implemented at the start of the next
session. The Acquisition tab is only available in the Living Image software that controls
the IVIS® Imaging System.
195
B. Preferences
B.1 General Preferences
Figure B.1 General preferences
Table B1 General preferences
Item
Description
Start Up Defaults
Dock Tool Palette
Sets the position of the tool palette in the application window.
Choose left or right.
Note: To undock the tool palette, click on the palette title bar and
drag it a distance greater than its width.
Window Size
Specifies the dimensions of the main application window.
Width, Height
Sets the dimensions of the image window.
Restore Defaults
Click to apply the default settings.
Apply Individual Color
Scale for Sequences
Choose this option to apply a separate color scale to each
thumbnail of a sequence. If this option is not chosen, all of the
thumbnails are displayed using the same color scale.
Show Transillumination
Locations
Choose this option to display a cross hair at each transillumination
location when you load transillumination data. When you mouse
over a cross hair, a tool tip displays the transillumination
coordinates. If this option is not chosen, you can choose the
Transillumination Location option in the sequence view window to
display the transillumination locations.
Show Advanced Options
If this option is chosen, the tool palette includes the point source
fitting tools and the image window includes the Colorized View tab.
Show Activity Window on: A drop-down list of options for when to display the activity log
(Figure B.2).
Save Settings
196
Color Selections
Applies the color settings of the active image data to subsequently
opened image data.
Folder Locations
Sets the default folder path to the current folder path setting. Click
the Export button
in the image window to view the current
folder path setting (Figure B.2).
Living Image® Software User’s Manual
Table B1 General preferences (continued)
Item
Description
Window Size &
Position
Applies the active image window size and position settings to
subsequently opened image data.
Most Recently Used
Dataset History
Applies the active image window size and position settings to
subsequently opened image data.
Display ROI Label As
Measurement
Photons
Select the type of measurement (in photons) to show in the ROI
label.
Counts:
Select the type of measurement (in counts) to show in the ROI
label.
Some of the general preferences specify how the main application window is organized.
Tool palette
Activity window (hidden by default)
Figure B.2 Main application window
To undock the tool palette, click on the palette title bar and drag it a distance greater than its
width. To dock the tool palette in the main window, drag the palette to the right or left side of
the window and release.
197
B. Preferences
B.2 User Preferences
Figure B.3 User preferences
Table B2 User preferences
Item
Description
User’s Settings
Existing User ID
The user ID displayed in the log on dialog box at startup.
New User ID
Opens the Add New User box. A new user is added to the
Existing User ID drop-down list.
Delete User ID
Deletes the user selected from the Existing User ID drop-down
list.
Preferences/Defaults
198
Label Name
Drop-down list of factory installed label name sets.
Edit User label
Choices
Opens a dialog box that enables you to edit a label set.
Default Units
Specifies the units (photons or counts) for image display.
Living Image® Software User’s Manual
B.3 Acquisition
Figure B.4 Acquisition preferences, Auto Exposure
Table B3 Auto exposure settings
Item
Description
Luminescent/Fluorescent Auto
Exposure Preferences
First Preference
Second Preference
Third Preference
During auto exposure, the software acquires a
bioluminescence or fluorescence image so that the brightest
pixel is approximately equal to the user-specified target max
count.
If the target max count cannot be closely approximated by
adjusting the first preference (for example, exposure time),
the software uses the first and second or first, second and
third preferences to attempt to reach the target max count
during image acquisition.
Target Max Count
Range Values
Exp Time (sec)
F/Stop
Binning
A user-specified intensity.
The minimum and maximum values define the range of
values for exposure time, F/Stop, or binning that the software
can use to attempt to reach the target max count during
image acquisition.
199
B. Preferences
B.4 Theme
Click to apply the
factory set defaults.
Click so select a different color or define a custom color.
Figure B.5 Theme preferences
Table B4 Theme preferences
Item
Description
3D View Background Color
Solid Color
Choose this option to apply a non-gradient background color to
the 3D view in the image window.
Gradient Color
Choose this option to apply a gradient background color to the 3D
view in the image window (Figure B.6). Top = the color at the
top of the window; Bottom = the color at the bottom of the
window.
Preferred Color Palette
Luminescent
The color scale that is used to display luminescent images. Click
Reverse to reverse the color scale.
Fluorescent
The color scale that is used to display fluorescent images. Click
Reverse to reverse the color scale.
Use saved colors while
loading data
If this option is chosen, data are displayed using a user-specified
color palette. For example, after you load data, specify a color
table in the Image Adjust tools, and save the data. The userspecified color table is automatically applied whenever the data
are loaded.
Preferred ROI Line Color
200
Luminescent
Color of the ROI outline on a luminescent image.
Fluorescent
Color of the ROI outline on a fluorescent image.
Living Image® Software User’s Manual
Figure B.6 Image window, 3D view with gradient background
B.5 Tissue Properties
Figure B.7 Set tissue properties preferences (left) for the Properties tab in the Planar Spectral
Imaging, DLIT, or FLIT tools.
Table B5 Tissue properties preferences
Item
Description
Tissue Properties
Choose a default tissue type that is most representative of the area
of interest.
Source Spectrum
Choose the default luminescent source.
201
B. Preferences
Table B5 Tissue properties preferences (continued)
Item
Description
Index of Refraction
The software automatically sets the internal medium index of
refraction based on the selection in the Tissue Properties list
Plot
Tissue Properties
Choose this option to display a graph of the absorption coefficient
(μa), effective attenuation coefficient (μeff), and reduced scattering
coefficient (μ’s or μsp).
Source Spectrum
Choose this option to display the source spectrum.
Apply to
DLIT/FLIT
Choose this option if the settings are for the Properties tab in the
FLIT or DLIT tools.
Planar Spectral
Imaging
Choose this option if the settings are for Properties tab in the Planar
Spectral Imaging tools.
B.6 3D Analysis
Figure B.8 Set 3D analysis preferences (left) for the DLIT reconstruction tools (right)
Table B6 3D analysis preferences
202
Item
Description
System
Select the IVIS Imaging System from the drop-down list.
Angle Limit (deg)
The angle between the object surface normal and the optical axis. For
more details, see page 253.
Kappa Limits
Kappa (κ) is a parameter that is searched during a reconstruction to
determine the best fit to the image data. Small values of kappa tend to
favor deeper sources, while large values favor more shallow sources. For
more details, see page 254.
Living Image® Software User’s Manual
Table B6 3D analysis preferences (continued)
Item
Description
N Surface Limits
The maximum number of surface intensity points to use in the
reconstruction at a given wavelength. The range is 200 to 800 and the
default is 200. The time required for reconstruction is shortest for smaller
values of N (for example, 200). However, a large N value may give a more
accurate result because more data are included in the fit.
Voxel Size Limits
Voxels are the small cubes of space inside a subject, each of which
contains a light source (much like a pixel in a 2D image). The DLIT
reconstruction begins with large voxels, specified by the voxel size limit
(the length of a side of the voxel cube in mm). At each iteration, the
algorithm reduces the size of the voxel by a factor of two until the
optimum solution is found.
The voxel size limits are a minimum of five and a maximum of 10. The
default range is set to 6-9 mm. A larger range of voxel limits ensures a
more reliable solution, but requires more computational time. The default
range of 6-9 is usually adequate to determine the optimum solution.
Voxel Size
Increment
This is the step increment in voxel size, stepping from the minimum voxel
size limit to the maximum voxel size limit. For example, if the voxel size
limit ranges from 6-9 mm, a voxel size increment = 1 gives four starting
voxel sizes (6, 7, 8, and 9 mm).
The default increment of 1 mm is usually adequate, however smaller
increments can be used if you want to sample finer voxel sizes. Smaller
increments will significantly increase the time required for
reconstruction.
Uniform Surface
Sampling
If this option is chosen, the surface data for each wavelength will be
sampled spatially uniformly on the signal area. If this option is not chosen,
the maximum ‘N surface elements’ will be sampled for the data. This
means that the N brightest surface elements will be used as data in the
reconstruction. Typically, non-uniform sampling is recommended if there
is a single bright source, while uniform sampling is preferred if there are
several scattered sources.
NNLS + Simplex
Optimization
If this option is not chosen, the software uses a linear programming
algorithm to seek the solution (Simplex solution). If this option is chosen,
the software also applies a non-negative least squares optimization
algorithm at each iteration to provide a better solution for source power.
The Simplex solution is more robust, but tends to underestimate the
source flux in each voxel. Therefore, the NNLS + Simplex option is
recommended.
NNLS Weighted Fit
Choose this option to weight the wavelength data proportionally to its
intensity in the NNLS reconstruction. This option is especially useful if the
intensity of longer wavelength data is orders of magnitude greater than
the intensity of shorter wavelength data.
203
B. Preferences
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204
Living Image® Software User’s Manual
Appendix C Detection Sensitivity
CCD Detection Efficiency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205
Binning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206
Smoothing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208
The parameters that control the number of photons collected (signal) and the image
background (noise) determine the sensitivity of low light imaging. To maximize
sensitivity, the goal is to increase signal and decrease background
Several factors affect the number of photons collected, including the lens f/stop, image
magnification, size and detection efficiency (quantum efficiency) of the CCD, transport
efficiency of the imaging optics, and the image exposure time.
C.1 CCD Detection Efficiency
IVIS® Imaging Systems use a back-thinned, back-illuminated CCD cooled to -90° to 105° C (depending on the system). This type of CCD provides high quantum efficiency of
over 80% across the visible and near infrared part of the spectrum.
Figure C.1 shows detection efficiencies for several commonly used photon detectors. The
back-illuminated CCD has the highest efficiency, particularly in the 600-800 nm region of
the spectrum, the area of greatest interest for in vivo imaging.
Figure C.1 Quantum efficiencies
Bialkali photocathode (▲), back-illuminated CCD (◆), and front-illuminated CCD (■). IVIS
systems use back-illuminated CCDs.
Lens Aperture
IVIS® Imaging Systems are equipped with a high-light-collection f/1 lens. The sensitivity
of the IVIS Imaging System can be adjusted by changing the f/stop setting that controls the
lens aperture. The detected signal scales approximately as 1/(f/stop)2. For maximum
sensitivity, select f/1, the largest aperture setting on the IVIS Imaging System (Figure C.2).
This provides the greatest light collection efficiency, but results in the minimum depth of
field for the image. The depth of field refers to the depth over which the image appears to
be in focus and is determined by the f/stop and the field of view (FOV).
205
C. Detection Sensitivity
At f/1, the depth of field ranges from ~0.2 cm at FOV= 3.9 cm (IVIS® Imaging System
200 Series only) to ~2 cm at FOV= 25 cm. You can use the manual focus option on the
Control panel to easily assess the depth of field at any f/stop and FOV setting. For more
details on manual focusing, see page 34. Generally f/1 is recommended for low light
luminescent images and f/2 or f/4 is recommended for brighter luminescent or fluorescent
images.
Figure C.2 Lens f/stop positions.
Left: lens wide open at f/1; right: lens closed down at f/8.
Image Exposure Time
The image exposure time also affects sensitivity. The number of photons collected is
directly proportional to the image exposure time. For example, an image acquired over a
two minute exposure contains twice as many detected photons as an image acquired over
a one minute exposure. Longer exposure times are usually beneficial when imaging very
dim samples. However, this may not always be true because some types of background,
dark charge in particular, increase with exposure time. (For more details on backgrounds,
see Appendix E, page 217.) An IVIS® Imaging System has extremely low background
that enables exposures of up to 30 minutes. However, animal anesthesia issues and
luciferin kinetics limit practical exposure times for in vivo imaging to 5-10 minutes.
Field of View (FOV)
The FOV indirectly affects sensitivity. Changing the FOV without changing the binning
or the f/stop does not significantly affect sensitivity. However, CCD pixels are effectively
smaller at a smaller FOV (higher magnification) so that higher levels of binning can be
applied without loss of spatial resolution.
For example, an image acquired at binning=4 and FOV=20 cm has the same spatial
resolution as an image acquired at binning=8 and FOV=10 cm. Due to the increase in
binning, the latter image has a four-fold increase in sensitivity compared to the former.
C.2 Binning
A charge coupled device (CCD) is a photosensitive detector constructed in a twodimensional array of pixels. After an image is acquired, each pixel contains an electrical
charge that is proportional to the amount of light that the pixel was exposed to. The
software measures the electrical charge of each CCD pixel and assigns a numerical value
(counts). (For more details on counts and other measurement units, see Appendix D,
page 211.) The resulting image data comprise a two-dimensional array of numbers; each
pixel contains the counts associated with the amount of light detected.
206
Living Image® Software User’s Manual
The IVIS® Imaging Systems are equipped with a CCD that ranges from 1024× 1024 to
2048× 2048 pixels in size, and thus have a high degree of spatial resolution. At binning=1,
each pixel is read and the image size (number of pixels) is equal to the physical number of
CCD pixels (Figure C.3).
Binning = 1
CCD pixel
Binning = 2
Signal 4 times larger.
Spatial size doubled.
Binning = 4
Signal 16 times larger.
Spatial size quadrupled.
Figure C.3 A small segment of the CCD.
At binning = 2, 4 pixels are summed together; at binning = 4, 16 pixels are summed.
At binning=2, four pixels that comprise a 2× 2 group on the CCD are summed prior to read
out and the total number of counts for the group is recorded (Figure C.3). This produces a
smaller image that contains one fourth the pixels compared to an image at binning=1.
However, due to summing, the average signal in each pixel is four times higher than at
binning=1. At binning=4, 16 pixels are summed prior to read out.
Binning significantly affects the sensitivity of the IVIS Imaging System. Binning at higher
levels (for example, ≥ 4) improves the signal-to-noise ratio for read noise, an electronic
noise introduced into the pixel measurement at readout. If four pixels are summed before
readout, the average signal in the summed pixel (super pixel) is four times higher than at
binning=1.
The read noise for the super pixel is about the same as it was for the individual pixels.
Therefore, the signal-to-noise ratio for the read noise component of the image noise is
improved by a factor of four. Read noise is often the dominant source of noise in in vivo
images, so a high binning level is a very effective way to improve the signal-to-noise ratio.
Unfortunately, binning reduces the spatial resolution in an image. For example, at
binning=2, a super pixel is twice as wide as a pixel at binning=1. This results in a factor of
two loss in image spatial resolution. However, for in vivo imaging, the added sensitivity is
usually more important than the spatial resolution. Further, since in vivo signals are often
diffuse due to scattering in tissue, little is gained by increasing spatial resolution. (For more
background on the propagation of light through tissue, see Diffusion Model of Light
Propagation Through Tissue, page 240.) In such cases, high levels of binning may be
appropriate (up to 10 or 16, depending on the CCD of the IVIS® Imaging System). If signal
levels are high enough that sensitivity is not an issue, then it is better to image at a lower
binning level (two or four) in order to maintain a higher degree of spatial resolution.
NOTE
For application-specific questions regarding the appropriate binning level, please
contact Xenogen Corporation.
207
C. Detection Sensitivity
The IVIS System Control panel provides several binning options. The actual binning
numbers associated with these settings depends on the CCD chip and type of image (Table
C.1). These choices should satisfy most user needs. However, if you want to manually
control binning, you can specify Manual Binning in the Living Image Tools-PreferenceCamera Settings box.
Table C.1 Binning settings
Binning
Camera
EEV
ROPER
SITe
Andor
Medium Lumin
Bin 8
Bin 5
Bin 4
Bin 4
Small (high-resolution)
Lumin
Bin 4
Bin 2
Bin 2
Bin 2
Large (high-sensitivity)
Lumin
Bin 16
Bin 10
Bin 8
Bin 8
Medium Photo
Bin 4
Bin 2
Bin 2
Bin 2
Small (high-resolution)
Photo
Bin 2
Bin 1
Bin 1
Bin 1
You can also apply soft binning after an image is acquired. Conceptually, soft binning is
the same as hardware binning⎯groups of pixels are summed and a smaller, lower
resolution image is produced. However, in soft binning the summing is performed
digitally on the stored image data, not on the electronic charge before readout as in
hardware binning.
Although soft binning does not improve the signal-to-noise ratio for read noise, it may
enhance the signal visibility because it reduces the statistical scatter of nearby pixel
contents. Usually, hardware binning is preferred, but if it is not possible to take another
image, applying soft binning to the data may provide a worthwhile solution.
C.3 Smoothing
Smoothing is a filtering method that reduces noise in the image data. To apply smoothing,
the software replaces the intensity of each pixel with the average intensity of a nearby
pixel neighborhood that includes the pixel. Figure C.4 shows a 3x3 pixel neighborhood.
Smoothing does not change the pixel size and helps:
• Eliminate outlier pixel values that are extremely high or low.
• Reduce noise (fluctuations) in the image to help reveal small signals.
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Center pixel value = the mean value of
the nine pixels in the 3x3 neighborhood
Figure C.4 3x3 pixel neighborhood
209
C. Detection Sensitivity
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Appendix D Image Data Display & Measurement
Image Data . . . . . . .
Quantifying Image Data
Flat Fielding . . . . . .
Cosmic Ray Corrections
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213
216
216
D.1 Image Data
Scientific Image Data
Scientific image data is a two-dimensional array of numbers. Each element of the array
(pixel) is associated with a number that is proportional to the light intensity on the element.
A charge coupled device (CCD) camera used for scientific imaging is essentially an array
of photo-sensitive pixels and each pixel collects photons during an image exposure.
The subsequent electronic readout provides a photon intensity number associated with
each pixel. In a bright area of the image, more photons are detected and the photon intensity
number is greater than the number in a dim area of the image.
The image data can be visualized in different ways, including pseudocolor images
(generated by the Living Image® software), contour plots, or isometric displays.
Graphic Image Data
A graphic image is a two-dimensional array of pixels with a color assigned to each pixel.
There are several schemes for digitally storing the images. For example, a common scheme
assigns a red-green-blue (RGB) color code to each pixel. The RGB code defines how much
of each color to apply in order to create the final pixel color. Color photographs or color
screenshots are examples of RGB images.
An RBG image is also a two-dimensional array of numbers, but unlike a scientific image,
the numbers are only color codes and are not related to light intensity. A graphic image can
be exported to a graphic display application.
Pseudocolor Images
An image can be generated from scientific image data by assigning a color to each
numerical value and plotting the array so that each pixel is filled with the color that
corresponds to its numerical value. A color table defines the relationship between the
numerical data and the displayed color. For example, a grayscale color table assigns black
to the smallest number in the array, white to the largest number, and shades of gray to the
values in between (Figure D.1). The resulting image is equivalent to a black and white
photograph. An illuminated photographic image acquired on an IVIS® Imaging System is
an example of a grayscale pseudoimage.
The reverse rainbow color table is also commonly used and assigns violet to the smallest
number on the array, red to the largest number, and all of the spectral colors of the rainbow
to the values in between (Figure D.1).
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D. Image Data Display & Measurement
A photographic image is a gray scale pseudoimage.
In Overlay display mode, a pseudocolor image of the
luminescent data is overlaid on a photographic image.
Color table associated with the data.
Figure D.1 Example pseudoimages
A pseudocolor scheme is typically used to display the numerical contents of scientific
image data like the luminescent or fluorescent images acquired on an IVIS® Imaging
System. The pseudocolor scheme makes it easy to see areas of bright light emission. The
amount of light emission can be quantified using measurement ROIs. (For more details,
Measuring ROIs in an Image, page 84.)
Measurement data is independent of the colors displayed in the pseudocolor image. You
can change the appearance of the image data without affecting the underlying numeric
pixel values. For example, you apply a different color table to the data or adjust the range
of numeric values associated with the color table. Measurements that quantify pixel data
produce the same results independent of the appearance of the pseudocolor display.
A pseudocolor image can be converted to an RGB color code and saved as an RGB image.
The RGB image looks like a pseudocolor image, but does not include the numerical
information derived from the light detected in each pixel. Therefore, the amount of light
in an RGB image cannot be quantified.
Overlays
212
In the overlay display mode, the pseudocolor luminescent or fluorescent image is
displayed on the associated grayscale photographic image (Figure D.1). Pixels in the
luminescent or fluorescent image that are less than the minimum color table setting are not
displayed. As a result, the lowest intensity color in the table is transparent and this enables
you to view the underlying photographic image in regions where the luminescent light
emission is low.
Living Image® Software User’s Manual
D.2 Quantifying Image Data
The Living Image software can quantify and display scientific image data using three types
of measurements (Figure D.1):
• Counts
• Photons
• Efficiency (for fluorescent images only)
Counts
Data
Display
Choose This to Display:
Recommended For:
Counts
An uncalibrated measurement of the
photons incident on the CCD camera.
Image acquisition to ensure that the
camera settings are property adjusted.
Photons
A calibrated measurement of the photon ROI measurements on bioluminescent
emission from the subject.
images.
Efficiency
A fluorescence emission image
normalized to the incident excitation
intensity (radiance of the subject/
illumination intensity).
ROI measurements on fluorescent
images.
When image data is displayed in counts, the image pixel contents are displayed as the
numerical output of the charge digitizer on the charge coupled device (CCD) (Figure D.2).
The counts measurement (also known as analog digitizer units (ADU) or relative
luminescence units (RLU)) is proportional to the number of photons detected in a pixel.
Counts are uncalibrated units that represent the raw amplitude of the signal detected by the
CCD camera. A signal measured in counts is related to the photons incident on the CCD
camera. The signal varies, depending on the camera settings (for example, integration time,
binning, f/stop, or field of view setting).
All IVIS® Imaging Systems include a CCD digitizer that is a 16-bit device, which means
that the signal count range is from zero to 65,535. Sometimes the displayed signal count
may appear outside of this range due to corrections applied to the image data (for example,
background corrections).
Select Counts, Photons, or
Efficiency for the image data
In counts mode, the ROI measurements
include:
Total Counts = Sum of all counts for all
pixels inside the ROI
Average Counts = Total Counts/Number of
pixels or superpixels
Quantity ROI Pixels = Number of binned
pixels inside the ROI
Area (CCD pixels) = Number of unbinned
CCD pixels inside the ROI
Figure D.2 Image window and ROI Measurements table (counts mode)
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D. Image Data Display & Measurement
Photons
When image data is displayed in photons, the photon emission from the subject or
radiance is displayed in photons/sec/cm2/sr. Counts are a relative measure of the photons
incident on the CCD camera and photons are absolute physical units that measure the
photon emission from the subject.
The radiance unit of photons/sec/cm2/sr is the number of photons per second that leave a
square centimeter of tissue and radiate into a solid angle of one steradian (sr) (Figure D.3).
Figure D.3 Isotropic radiation
Isotropic radiation from a cell is called photon flux (photons/sec). When cells occur in tissue,
photon emission from the tissue surface is called surface radiance (photons/sec/cm2/sr).
A steradian can be thought of as a three-dimensional cone of light emitted from the surface
that has a unit solid angle. Much like a radian is a unit of arc length for a circle, a steradian
is a unit of solid angle for a sphere. An entire sphere has 4π steradians. Lens systems
typically collect light from only a small fraction of the total 4π steradians.
When image data is displayed in photons mode, the units change to photons/sec/cm2/sr.
These are units of photon radiance on the surface of the animal. A very important
distinction between these absolute physical units and the relative units of counts is that the
radiance units refer to photon emission from the subject animal itself, as opposed to counts
that refers to photons incident on the detector.
Measurements in units of radiance automatically take into account camera settings (for
example, integration time, binning, f/stop, and field of view). As a result, images of the
same subject acquired during the same session have the same signal amplitude regardless
of the camera settings because the radiance on the animal surface does not change. The
advantage of working with image data in photons mode is that camera settings can be
changed during an experiment without having to adjust the images or the measured ROI
data. Images or ROI data can be quantitatively compared across different IVIS® Imaging
Systems.
Xenogen Corporation calibrates the camera settings of each IVIS Imaging System at 600
nm. The response of the CCD is relatively flat (~10%) over the range from 500-700 nm
which includes the spectral variation found in bacterial or firefly luciferase. Therefore,
calibration is accurate over this range.
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Living Image® Software User’s Manual
Efficiency
The fluorescent signal detected from a sample depends on the amount of fluorophore
present in the sample and the intensity of the incident excitation light. The excitation light
incident on the sample stage is not uniform over the field of view (FOV). At FOV=10, there
is a slightly dished illumination profile due to the close proximity of the stage to the
illumination reflectors, while the profiles for the other stage locations are peaked near their
center. The illumination intensity profile varies by up to ±30% across the entire FOV
(Figure D.4).
Figure D.4 Illumination profiles at different FOVs
Measurements were taken at the center of the FOV on the IVIS Imaging System 100 Series.
Displaying fluorescent image data in terms of efficiency eliminates the variable excitation
light from the measurement and enables a more quantitative comparison of fluorescent
signals. When you select efficiency for the image data (Figure D.2), the software normalizes
the fluorescent emission image to a reference image and computes:
Efficiency = Radiance of the subject/Illumination intensity
Prior to instrument delivery, Xenogen Corporation generates a reference image of the
excitation light intensity (no emission filter) incident on a highly reflective white plate for
each excitation filter at every FOV and lamp power. The data are stored in the Living
Image folder.
Image efficiency data does not have units. The efficiency number for each pixel represents
the fraction of fluorescent photons relative to each incident excitation photon and is
typically in the range of 10-2 to 10-9. When ROI measurements are made, the total efficiency
within the ROI is the efficiency per pixel integrated over the ROI area, so the resulting units
of total efficiency is area or cm2.
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D. Image Data Display & Measurement
D.3 Flat Fielding
Flat fielding refers to the uniformity of light collected across the field of view (FOV). A
lens usually collects more light from the center of the FOV than at the edges. The Living
Image® 3.0 software provides a correction algorithm to compensate for the variation in the
collection efficiency of the lens. This enables uniform quantitation of ROI measurements
across the entire FOV.
To apply the correction algorithm, choose the Flat Field Correction option in the
Corrections/Filtering tools. The algorithm multiplies each pixel by a predetermined scale
factor. The scale factor for each pixel depends on its distance from the center of the image.
The scale factor near the center of the field of view is one, but can be up to two or three
near the corners on the IVIS® Imaging System 100 Series. (The IVIS Imaging System 200
Series has a larger lens with a smaller flat field correction.)
You may notice an increase in noise near the edges and corners of the FOV when flat field
correction is applied– this is normal.
D.4 Cosmic Ray Corrections
Cosmic rays are extraterrestrial high-energy particles that register a false signal on a CCD
detector. Cosmic rays as well as other sources of ionizing radiation cause infrequent
interactions (a few per minute) on the CCD. These interactions result in large signals that
are usually isolated to a single pixel, making them easy to correct.
The Living Image® 3.0 software searches for isolated, high amplitude hot pixels and
replaces them with a collective average of surrounding pixels. The Cosmic Correction
option should always be selected for in vivo image data because hot pixels can
significantly affect an ROI measurement.
Cosmic ray correction is not recommended when imaging very small objects such as
individual cells. An individual cell may only light up one or two pixels and can sometimes
be misinterpreted as a cosmic ray. In this case, clear the Cosmic Correction option in the
Corrections/Filtering tools to avoid filtering out single-cell images.
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Appendix E Luminescent Background Sources & Corrections
Electronic Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217
Background Light On the Sample . . . . . . . . . . . . . . . . . . . . . . . . 218
Background Light From the Sample . . . . . . . . . . . . . . . . . . . . . . . 220
The background sources of light from bioluminescent images are inherently very low. This
appendix discusses sources of background and how to manage them. Due to the extreme
sensitivity of the IVIS® Imaging System, residual electronic background (dark current) and
luminescent emission from live animals (autoluminescence) are measurable and must be
taken into account.
For information on fluorescent background, see Appendix F, page 229.
E.1 Electronic Background
The cooled CCD camera used in an IVIS Imaging System has electronic background that
must be accurately measured and subtracted from the image data before the light intensity
is quantified. Raw data that is not corrected for electronic background results in erroneous
ROI measurements. Incorrect background subtraction may also result in serious errors.
However, it is not necessary to subtract the electronic background when making a simple
visual inspection of an image.
The types of electronic background include:
• Read bias - An electronic offset that exists on every pixel. This means that the zero
photon level in the readout is not actually zero, but is typically a few hundred
counts per pixel. The read bias offset is reproducible within errors defined by the
read noise, another quantity that must be determined for quantitative image
analysis.
• Dark current - Electronic background generated by the thermal production of
charge in the CCD. To minimize dark current, the CCD is cooled during use.
Read Bias & Drift
Prior to a luminescent image exposure, the Living Image® software initiates a series of
zero-time exposures (image readout) to determine a read bias measurement.
If a dark charge background is available for the luminescent image, the average bias offset
for the read bias image stored with the dark charge measurement is compared to the
average bias offset determined with the read bias measurement made prior to the image.
The difference, or drift correction, is stored with the luminescent image data, and is later
used to correct minor drift (typically less than two counts/pixel) that may occur in the bias
offset since measuring the dark charge background.
If a dark charge background is not available at the time of the luminescent image exposure,
the software checks to see if the selected image parameters warrant a dark charge
measurement (large binning and long exposure time). If a dark charge image is not
required, the read bias will be used. If a dark charge is recommended, the software provides
the option of using the read bias measurement instead. Since the read bias is by far the
largest component of background, using a read bias measurement instead of a dark charge
measurement is often acceptable. If read bias is used instead of a dark charge background,
217
E. Luminescent Background Sources & Corrections
the read bias image is stored with the image data rather than the usual background
information.
If the amount of dark charge associated with an image is negligible, read bias subtraction
is an adequate substitute for dark charge background subtraction. Dark charge increases
with exposure time and is more significant at higher levels of binning. A good rule of
thumb is that dark charge is negligible if:
τ B2 < 1000
where τ is the exposure time (seconds) and B is the binning factor.
Under these conditions, dark charge contributes less than 0.1 counts/pixel and may be
ignored.
Dark Charge
Dark charge refers to all types of electronic background, including dark current and read
bias. Dark charge is a function of the exposure time, binning level, and camera
temperature. A dark charge measurement should be taken within 48 hours of image
acquisition and the system should remain stable between dark charge measurement and
image acquisition. If the power to the system or camera controller (a component of some
IVIS Systems) has been cycled or if the camera temperature has changed, a new dark
charge measurement should be taken.
The dark charge is measured with the camera shutter closed and is usually performed
automatically overnight by the Living Image® software. The software acquires a series of
zero-time exposures to determine the bias offset and read noise, followed by three dark
exposures. The dark charge measurement usually takes more than three times as long to
complete as the equivalent luminescent exposure.
E.2 Background Light On the Sample
An underlying assumption for in vivo imaging is that all of the light detected during a
luminescent image exposure is emitted by the sample. This is not accurate if there is an
external light source illuminating the sample. Any reflected light will be detected and is
indistinguishable from emission from the sample.
The best way to deal with external light is to physically eliminate it. There are two
potential sources of external light: a light leak through a crack or other mechanical
imperfection in the imaging chamber or a source of external illumination.
IVIS® Imaging Systems are designed to be extremely light tight and are thoroughly
checked for light leaks before and after installation. Light leaks are unlikely unless
mechanical damage has occurred. To ensure that there are no light leaks in the imaging
chamber, conduct an imaging test using the Xenogen High Reflectance Hemisphere
(Figure E.1).
A more subtle source of external illumination is the possible presence of light emitting
materials inside the imaging chamber. In addition to obvious sources such as the light
emitting diodes (LEDs) of electronic equipment, some materials contain phosphorescent
compounds.
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NOTE
Do not place equipment that contains LEDs in the imaging chamber.
Phosphorescence is a physical process similar to fluorescence, but the light emission
persists for a longer period. Phosphorescent materials absorb light from an external source
(for example, room lights) and then re-emit it. Some phosphorescent materials may re-emit
light for many hours. If this type of material is introduced into the imaging chamber, it
produces background light even after the chamber door is closed. If the light emitted from
the phosphorescent material illuminates the sample from outside of the field of view during
imaging, it may be extremely difficult to distinguish from the light emitted by the sample.
IVIS® Imaging Systems are designed to eliminate background interference from these
types of materials. Each system is put through a rigorous quality control process to ensure
that background levels are acceptably low. However, if you introduce such materials
inadvertently, problems may arise.
Problematic materials include plastics, paints, organic compounds, plastic tape, and plastic
containers. Contaminants such as animal urine can be phosphorescent. To help maintain a
clean imaging chamber, place animal subjects on black paper (for example, Artagain black
paper, Strathmore cat. no. 445-109) and change the paper frequently. Cleaning the imaging
chamber frequently is also helpful.
!
IMPORTANT
ALERT! Use only Xenogen approved cleaning agents. Many cleaning compounds
phosphoresce! Contact Xenogen technical support for a list of tested and approved
cleaning compounds.
If it is necessary to introduce suspect materials into the imaging chamber, screen the
materials by imaging them. Acquire an image of the material alone using the same settings
(for example, FOV and exposure time) that will be used to image the sample to determine
if the material is visible in the luminescent image.
Microplates (white, black, or clear plastic) can be screened this way. Screen all three types
with a test image. White plates appear extremely bright by IVIS® Imaging System
standards and interfere with measurements. Black or clear plastic microplates do not
phosphoresce, making them better choices.
The Xenogen High Reflectance Hemisphere provides a more definitive way to determine
the presence of an undesirable light source (Figure E.1). It is a small white hemisphere that
is coated with a non-phosphorescent material. A long exposure image of the hemisphere
should produce a luminescent image in which the hemisphere is not visible.
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E. Luminescent Background Sources & Corrections
Figure E.1 Xenogen High Reflectance Hemisphere and a plastic marker pen
Left: Photographic image. Right: Photograph with luminescent overlay. The hemisphere is
illuminated by phosphorescence emitted from the pen.
If any part of the hemisphere exhibits what appears to be luminescent emission, it is
actually the light reflected from a source illuminating the hemisphere. Observe the side of
the hemisphere that is illuminated to help determine the source location.
In Figure E.1 the pen appears very bright due to phosphorescent emission that is also
illuminating the portion of the hemisphere next to the pen. If the pen had been outside the
field of view, it would not have been imaged, and the source of the phosphorescence
would be less obvious. However, the illumination of the hemisphere would still be very
apparent and indicative of a light pollution problem.
!
IMPORTANT
ALERT! Handle the Xenogen High Reflectance Hemisphere by its black base plate
while wearing cotton gloves provided by Xenogen. Skin oils can phosphoresce and
will contaminate the hemisphere. Latex gloves and the powder on them may also
phosphoresce. If the hemisphere becomes contaminated, contact Xenogen technical
support for a replacement. There are no known agents that can clean the
hemisphere. To check the hemisphere for contamination, take several images of the
hemisphere, rotating it slightly between images. A glowing fingerprint, for example,
will rotate with the hemisphere, while a glowing spot due to external illumination most
likely will not.
E.3 Background Light From the Sample
Another source of background is the natural light emitted from a sample that is not due to
emission from the source of interest in the sample. This type of background may be due
to a material associated with the experimental setup. For example, the cell culture medium
may phosphoresce. Materials should be screened so you can identify and eliminate
problematic materials. If a background source is phosphorescent and the phosphorescent
lifetime is relatively short, you can try keeping the sample in the dark for a long period
before imaging to reduce background light emission.
Occasionally there is no way to eliminate the natural light emission of the sample. The
natural light emission associated with living animals (autoluminescence) is a major area
of interest in in vivo bioluminescent imaging. Most animals exhibit a low level of
autoluminescence. Usually this is only a problem when looking for very low signals at the
highest levels of sensitivity.
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Xenogen Corporation has conducted tests to try to minimize the source of the background
light emission in mice.
Test Description
Observation
Test 1: Subject animals were
Background emission levels were not reduced. A
housed in the dark 12 hours prior phosphorescent component in mouse fur or skin is not the
to imaging.
source of light emission.
Test 2: White-furred animals
were shaved prior to imaging
No increase or decrease in background emission levels.
Test 3: Alfalfa (known to be
An alfalfa-free diet reduced background emission slightly, but
phosphorescent) was eliminated not significantly.
from the animal diet.
The sources of autoluminescence are not yet fully understood. No external sources have
been proven to cause natural light emissions, so it is possible that a chemiluminescent
process associated with metabolic activity in living animals is the source of animal
background. This is supported by the observation that the level of background light drops
significantly in euthanized animals.
In Figure E.2 the background light emission is clearly visible in the images of a control
white-furred mouse and a nude mouse. The images are five minute, high-sensitivity (high
binning) exposures. The average emission from a white-furred mouse and a nude mouse is
approximately 1600 photons/s/cm2/sr and 1000 photons/s/cm2/sr, respectively. Since these
values are well above the lower limit of detection of the IVIS® Imaging System (~100
photons/s/cm2/sr), the background light emission from the mouse determines the limit of
detection.
An approximation of this background (determined by making similar measurements on
either control animals or regions of the subject animal that do not contain the primary
signal) can be subtracted from ROI measurements. (For more information on ROI
measurements, see Chapter 6, page 91.)
Note that the background light emission is not uniform over the entire animal. In Figure E.2
images of control animals (mice) show a somewhat higher background component
originating from the abdominal and thoracic regions. Therefore, care must be taken when
selecting a representative background area.
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E. Luminescent Background Sources & Corrections
Photograph
Luminesce
nt overlay
Photograph
Luminescent
overlay
Figure E.2 Background light emission
Background light emission from a female white furred (Swiss Webster) (left) and a female
nude (Nu/nu) mouse (right).
Usually only very low signals at the highest level of sensitivity require this type of
background subtraction. For more information on how best to handle these types of
measurements, please contact Xenogen technical support.
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Appendix F Fluorescent Imaging
Description and Theory of Operation . . . . . . . . . . . . . .
Filter Spectra . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Working with Fluorescent Samples . . . . . . . . . . . . . . .
Image Data Display . . . . . . . . . . . . . . . . . . . . . . . .
Fluorescent Background . . . . . . . . . . . . . . . . . . . . .
Subtracting Instrument Fluorescent Background . . . . . . . .
Adaptive Background Subtraction . . . . . . . . . . . . . . . .
Subtracting Tissue Autofluorescence Using Background Filters
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235
235
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F.1 Description and Theory of Operation
System Components
The IVIS® Imaging System 200 Series and IVIS Lumina offer built-in fluorescence
imaging capability as standard equipment. The IVIS Imaging System 100 and 50 Series
use the XFO-6 or XFO-12 Fluorescence Option to perform fluorescence imaging. The
fluorescence equipment enables you to conveniently change between bioluminescent and
fluorescent imaging applications (Figure F.1). For more details, see the IVIS Imaging
System 200 Series System Manual, the IVIS Lumina System Manual, or the XFO-6 or XFO12 Fluorescence Option Manual.
IVIS Imaging System 200 Series
IVIS Lumina,
IVIS Imaging System 50 or 100 Series
Figure F.1 Fluorescent imaging hardware
A 150-watt quartz tungsten halogen (QTH) lamp with a dichroic reflector provides light
for fluorescence excitation. The relative spectral radiance output of the lamp/reflector
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F. Fluorescent Imaging
combination provides high emission throughout the 400-950 nm wavelength range
(Figure F.2). The dichroic reflector reduces infrared coupling (>700 nm) to prevent
overheating of the fiber-optic bundles, but allows sufficient infrared light throughput to
enable imaging at these wavelengths. The Living Image software controls the illumination
intensity level (off, low, or high). The illumination intensity at the low setting is
approximately 18% that of the high setting.
Figure F.2 Relative spectral radiance output for the quartz halogen lamp with dichroic reflector.
The lamp output is delivered to the excitation filter wheel assembly located at the back of
the IVIS® Imaging System (Figure F.3). Light from the input fiber-optic bundle passes
through a collimating lens followed by a 25 mm diameter excitation filter. The IVIS
Imaging System provides a 12-position excitation filter wheel, allowing you to select from
up to 11 fluorescent filters (five filters on older systems). A light block is provided in one
filter slot for use during bioluminescent imaging to prevent external light from entering
the imaging chamber. The Living Image software manages the motor control of the
excitation filter wheel.
Figure F.3 Excitation filter wheel cross section.
Following the excitation filter, a second lens focuses light into a 0.25 inch fused silica
fiber-optic bundle inside the imaging chamber. Fused silica fibers (core and clad), unlike
ordinary glass fibers, prevent the generation of autofluorescence.
The fused silica fiber bundle splits into four separate bundles that deliver filtered light to
four reflectors in the ceiling of the imaging chamber (Figure F.1). The reflectors provide a
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Living Image® Software User’s Manual
diffuse and relatively uniform illumination of the sample stage. Analyzing image data in
terms of efficiency corrects for nonuniformity in the illumination profile. When the
efficiency mode is selected, the measured fluorescent image is normalized to a reference
illumination image. (For more details on efficiency, see page 215.)
The emission filter wheel at the top of the imaging chamber collects the fluorescent
emission from the target fluorophore and focuses it into the CCD camera. All IVIS®
Imaging Systems require that one filter position on each wheel always be open for
bioluminescent imaging.
IVIS Imaging System
Number of Emission Filter
Wheel Positions
Number of Available
Fluorescence Filters
200 Series
24 (two levels, each with 12
positions)
22 (60 mm diameter)
Lumina
8
7
100 or 50
6
5 (75 mm diameter)
F.2 Filter Spectra
High quality filters are essential for obtaining good signal-to-background levels (contrast)
in fluorescence measurements, particularly in highly sensitive instruments such as the
IVIS® Imaging Systems. Figure F.4 shows typical excitation and emission fluorophore
spectra, along with idealized excitation and emission filter transmission curves. The
excitation and emission filters are called bandpass filters. Ideally, bandpass filters transmit
all of the wavelengths within the bandpass region and block (absorb or reflect) all
wavelengths outside the bandpass region. This spectral band is like a window,
characterized by its central wavelength and its width at 50% peak transmission, or full
width half maximum. Figure F.5 shows filter transmission curves of a more realistic nature.
Because the filters are not ideal, some leakage (undesirable light not blocked by the filter
but detected by the camera) may occur outside the bandpass region. The materials used in
filter construction may also cause the filters to autofluoresce.
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F. Fluorescent Imaging
100
10
1.0
0.1
0.01
0.001
Figure F.4 Typical excitation and emission spectra for a fluorescent compound.
The graph shows two idealized bandpass filters that are appropriate for this fluorescent
compound.
Figure F.5 Typical attenuation curves for excitation and emission filters.
In Figure F.5, the vertical axis is optical density, defined as OD = -log(T), where T is the
transmission. An OD=0 indicates 100% transmission and OD=7 indicates a reduction of
the transmission to 10-7.
For the high quality interference filters in the IVIS® Imaging Systems, transmission in the
bandpass region is about 0.7 (OD=0.15) and blocking outside of the bandpass region is
typically in the OD=7 to OD=9 range. The band gap is defined as the gap between the 50%
transmission points of the excitation and emission filters and is usually 25-50 nm.
There is a slope in the transition region from bandpass to blocking (Figure F.5). A steep
slope is required to avoid overlap between the two filters. Typically, the slope is steeper
at shorter wavelengths (400-500 nm), allowing the use of narrow band gaps of 25 nm. The
slope is less steep at infrared wavelengths (800 nm), so a wider gap of up to 50 nm is
necessary to avoid cross talk.
Fluorescent Filters and
Imaging Wavelengths
226
Eight excitation and four emission filters come standard with a fluorescence-equipped
IVIS Imaging System (Table F.1). Custom filter sets are also available. Fluorescent
Living Image® Software User’s Manual
imaging on the IVIS Imaging System uses a wavelength range from 400-950 nm, enabling
a wide range of fluorescent dyes and proteins for fluorescent applications.
For in vivo applications, it is important to note that wavelengths greater than 600 nm are
preferred. At wavelengths less than 600 nm, animal tissue absorbs significant amounts of
light. This limits the depth to which light can penetrate. For example, fluorophores located
deeper than a few millimeters are not excited. The autofluorescent signal of tissue also
increases at wavelengths less than 600 nm.
Table F.1 Standard filter sets and fluorescent dyes and proteins used with IVIS Imaging Systems.
Name
Excitation Passband (nm) Emission Passband (nm)
Dyes & Passband
GFP
445-490
515-575
GFP, EGFP, FITC
DsRed
500-550
575-650
DsRed2-1, PKH26, CellTracker™ Orange
Cy5.5
615-665
695-770
Cy5.5, Alexa Fluor® 660, Alexa Fluor® 680
ICG
710-760
810-875
Indocyanine green (ICG)
GFP Background
410-440
Uses same as GFP
GFP, EGFP, FITC
DsRed Background
460-490
Uses same as DsRed
DsRed2-1, PKH26, CellTracker™ Orange
Cy5.5 Background
580-610
Uses same as Cy5.5
Cy5.5, Alexa Fluor® 660, Alexa Fluor® 680
ICG Background
665-695
Uses same as ICG
Indocyanine green (ICG)
F.3 Working with Fluorescent Samples
There are a number of issues to consider when working with fluorescent samples,
including the position of the subject on the stage, leakage and autofluorescence,
background signals, and appropriate signal levels and f/stop settings.
Tissue Optics Effects
In in vivo fluorescence imaging, the excitation light must be delivered to the fluorophore
inside the animal for the fluorescent process to begin. Once the excitation light is absorbed
by the fluorophore, the fluorescence is emitted. However, due to the optical characteristics
of tissue, the excitation light is scattered and absorbed before it reaches the fluorophore as
well as after it leaves the fluorophore and is detected at the animal surface (Figure F.6).
The excitation light also causes the tissue to autofluoresce. The amount of autofluorescence
depends on the intensity and wavelength of the excitation source and the type of tissue.
Autofluorescence can occur throughout the animal, but is strongest at the surface where the
excitation light is strongest.
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F. Fluorescent Imaging
Figure F.6 Illustration of the in vivo fluorescence process.
At 600-900 nm, light transmission through tissue is highest and the generation of
autofluorescence is lower. Therefore it is important to select fluorophores that are active
in the 600-900 nm range. Fluorophores such as GFP that are active in the 450-600 nm
range will still work, but the depth of detection may be limited to within several
millimeters of the surface.
Specifying Signal
Levels and f/stop
Settings
Fluorescent signals are usually brighter than bioluminescent signals, so imaging times are
shorter, typically from one to 30 seconds. The bright signal enables a lower binning level
that produces better spatial resolution. Further, the f/stop can often be set to higher values;
f/2 or f/4 is recommended for fluorescence imaging. A higher f/stop improves the depth
of field, yielding a sharper image. For more details on the f/stop, see Lens Aperture,
page 205.
F.4 Image Data Display
Fluorescent image data can be displayed in units of counts or photons (absolute,
calibrated), or in terms of efficiency (calibrated, normalized). For more details, see
Quantifying Image Data, page 213.
If the image is displayed in photons, you can compare images with different exposure
times, f/stop setting, or binning level. When an image is displayed in terms of efficiency,
the fluorescent image is normalized against a stored reference image of the excitation light
intensity. Efficiency image data is without units and represents the ratio of emitted light
to incident light. For more details on efficiency, see page 215.
Fluorescent Efficiency
228
The detected fluorescent signal depends on the amount of fluorophore present in the
sample and the intensity of the incident excitation light. At the sample stage, the incident
excitation light is not uniform over the FOV. It peaks at the center of the FOV and drops
of slowly toward the edges (Figure F.7). To eliminate the excitation light as a variable from
the measurement, the data can be displayed in terms of efficiency (Figure F.8).
Living Image® Software User’s Manual
Figure F.7 Illumination profiles for different FOVs on an IVIS Imaging System 100 Series
measured from the center of the FOV.
To enable a more
quantitative
comparison of
fluorescent signals,
choose Efficiency.
Figure F.8 Fluorescent image data displayed in terms of efficiency
When efficiency is selected, the fluorescent image data is normalized (divided) by a
stored, calibrated reference image of the excitation light intensity incident on a highly
reflective white plate. The resulting image data is without units, typically in the range of
10-2 to 10-9.
NOTE
On every IVIS® Imaging System, a reference image of the excitation light intensity is
measured for each excitation filter at every FOV and lamp power. The reference
images are measured and stored in the Living Image folder prior to instrument
delivery.
F.5 Fluorescent Background
Autofluorescence
Autofluorescence is a fluorescent signal that originates from substances other than the
fluorophore of interest and is a source of background. Almost every substance emits some
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F. Fluorescent Imaging
level of autofluorescence. Autofluorescence may be generated by the system optics,
plastic materials such as microplates, and by animal tissue. Filter leakage, which may also
occur, is another source of background light.
The optical components of the IVIS® Imaging Systems are carefully chosen to minimize
autofluorescence. Pure fused silica is used for all transmissive optics and fiber optics to
reduce autofluorescence. However, trace background emissions exist and set a lower limit
for fluorescence detection.
To distinguish real signals from background emission, it is important to recognize the
different types of autofluorescence. The following examples illustrate sources of
autofluorescence, including microplates, other materials, and animal tissue.
Microplate Autofluorescence
When imaging cultured cells marked with a fluorophore, be aware that there is
autofluorescence from the microplate as well as native autofluorescence of the cell.
Figure F.9 shows autofluorescence originating from four different plastic microplates. The
images were taken using a GFP filter set (excitation 445-490nm, emission 515-575nm).
White polystyrene
Clear polypropylene
Clear polystyrene
Black polystyrene
Figure F.9 Examples of microplate autofluorescence emission
The black polystyrene plate emits the smallest signal while the white polystyrene plate emits
the largest signal. (Imaging parameters: GFP filter set, Fluorescence level Low, Binning=8,
FOV=15, f/1, Exp=4sec.)
Two types of autofluorescent effects may occur:
Overall glow of the material - Usually indicates the presence of autofluorescence.
Hot spots - Indicates a specular reflection of the illumination source (Figure F.10).
The specular reflection is an optical illumination autofluorescence signal reflecting
from the microplate surface and is not dependent on the microplate material.
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Figure F.10 Specular reflection.
The four symmetric hot spots on this black polystyrene well plate illustrate the specular
reflection of the illumination source. (Imaging parameters: GFP filter set, Fluorescence level
Low, Binning=8, FOV=15, f/1, Exp=4sec.)
Black polystyrene microplates are recommended for in vitro fluorescent measurements.
Figure F.9 and Figure F.10 show that the black polystyrene microplate emits the smallest
inherent fluorescent signal, while the white polystyrene microplate emits the largest signal.
The clear polystyrene microplate has an autofluorescent signal that is slightly higher than
that of the black microplate, but it is still low enough that this type of microplate may be
used.
Control cells are always recommended in any experiment to assess the autofluorescence of
the native cell.
Miscellaneous Material Autofluorescence
It is recommended that you place a black Lexan® sheet (Xenogen part no. 60104) on the
imaging stage to prevent illumination reflections and to help keep the stage clean.
NOTE
The black paper recommended for bioluminescent imaging (Swathmore, Artagain,
Black, 9"x12", Xenogen part no. 445-109) has a measurable autofluorescent signal,
particularly with the Cy5.5 filter set.
Figure F.11 shows a fluorescent image of a sheet of black Lexan on the sample stage, as
seen through a GFP filter set. The image includes optical autofluorescence, light leakage,
and low level autofluorescence from inside the IVIS® System imaging chamber. The ringlike structure is a typical background autofluorescence/leakage pattern. The image
represents the minimum background level that a fluorophore signal of interest must exceed
in order to be detected.
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F. Fluorescent Imaging
Figure F.11 Light from black Lexan
This image shows the typical ring-like structure of light from a sheet of black Lexan, a low
autofluorescent material that may be placed on the imaging stage to prevent illumination
reflections. (Imaging parameters: GFP filter set, Fluorescence level High, Binning=16,
FOV=18.6, f/2, Exp=5sec.)
Other laboratory accessories may exhibit non-negligible autofluorescence. The chart in
Figure F.12 compares the autofluorescence of miscellaneous laboratory materials to that
of black Lexan. For example, the autofluorescence of the agar plate with ampicillin is
more than 180 times that of black Lexan. Such a significant difference in autofluorescence
levels further supports the recommended use of black polystyrene well plates.
NOTE
It is recommended that you take control measurements to characterize all materials
used in the IVIS® Imaging System.
Figure F.12 Comparison of autofluorescence of various laboratory materials to that of black
Lexan
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Despite the presence of various background sources, the signal from most fluorophores
exceeds background emissions. Figure F.13 shows the fluorescent signal from a 96-well
microplate fluorescent reference standard (TR 613 Red) obtained from Precision
Dynamics Co. Because the fluorescent signal is significantly bright, the background
autofluorescent sources are not apparent.
Figure F.13 96 well plate fluorescent reference standard (TR 613 Red)
The fluorescent signal is strong enough to exceed background emissions. (Imaging
parameters: DsRed filter set, Fluorescence level Low, Binning=8, FOV=15, f/1, Exp=4sec.)
Reference standard TR 613 Red is available through Precision Dynamics Co, http://
www.pdcorp.com/healthcare/frs.html.
Animal Tissue Autofluorescence
Animal tissue autofluorescence is generally much higher than any other background source
discussed so far and is likely to be the most limiting factor in in vivo fluorescent imaging.
Figure F.14 shows ventral images of animal tissue autofluorescence for the GFP, DsRed,
Cy5.5, and ICG filter set in animals fed regular rodent food and alfalfa-free rodent food
(Harlan Teklad, TD97184). Animals fed the regular rodent diet and imaged using the GFP
and DsRed filter sets, show uniform autofluorescence, while images taken with the Cy5.5
and ICG filter sets show the autofluorescence is concentrated in the intestinal area.
The chlorophyll in the regular rodent food causes the autofluorescence in the intestinal
area. When the animal diet is changed to the alfalfa-free rodent food, the autofluorescence
in the intestinal area is reduced to the levels comparable to the rest of the body. In this
situation, the best way to minimize autofluorescence is to change the animal diet to alfalfafree rodent food when working with the Cy5.5 and ICG filter sets. Control animals should
always be used to assess background autofluorescence.
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F. Fluorescent Imaging
Figure F.14 Images of animal tissue autofluorescence in control mice (Nu/nu females)
Animals were fed regular rodent food (top) or alfalfa-free rodent food (bottom). Images were
taken using the GFP, DsRed, Cy5.5, or ICG filter set. The data is plotted in efficiency on the
same log scale.
Figure F.15 shows a comparison of fluorescence and bioluminescence emission in vivo. In
this example, 3× 106 PC3M-luc/DsRed prostate tumor cells were injected subcutaneously
into the lower back region of the animal. The cell line is stably transfected with the firefly
luciferase gene and the DsRed2-1 protein, enabling bioluminescent and fluorescent
expression. The fluorescence signal level is 110 times brighter than the bioluminescence
signal. However, the autofluorescent tissue emission is five orders of magnitude higher.
In this example, fluorescent imaging requires at least 3.8× 105 cells to obtain a signal
above tissue autofluorescence while bioluminescent imaging requires only 400 cells.
Figure F.15 Fluorescent (left) and bioluminescent (right) images of stably transfected, dualtagged PC3M-luc DsRed cells.
The images show the signal from a subcutaneous injection of 3x106 cells in an 11-week old
male Nu/nu mouse.
NOTE
When you make ROI measurements on fluorescent images, it is important to subtract
the autofluorescence background. For more details, see Subtracting Tissue
Autofluorescence, page 115.
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F.6 Subtracting Instrument Fluorescent Background
The fluorescence instrumentation on an IVIS® Imaging System is carefully designed to
minimize autofluorescence and background caused by instrumentation. However a
residual background may be detected by the highly sensitive CCD camera.
Autofluorescence of the system optics or the experimental setup, or residual light leakage
through the filters can contribute to autofluorescence background. The Living Image
software can measure and subtract the background from a fluorescence image.
Fluorescent background subtraction is similar to the dark charge bias subtraction that is
implemented in luminescent mode. However, fluorescent background changes day-to-day,
depending on the experimental setup. Therefore, fluorescent background is not measured
during the night, like dark charge background is.
After you acquire a fluorescent image, inspect the signal to determine if a fluorescent
background should be subtracted (Figure F.16). If background subtraction is needed,
remove the fluorescent subject from the imaging chamber and measure the fluorescent
background (select Acquisition →Fluorescent Background →Measure Fluorescent
Background on the menu bar). In the Living Image® software, the Sub Fluor Bkg check
box appears on the Control panel after a background has been acquired. You can toggle the
background subtraction on and off using this check box.
NOTE
The fluorescence background also contains the read bias and dark charge. Dark
charge subtraction is disabled if the Sub Fluor Bkg check box is checked.
Figure F.16 Comparison of dark charge bias subtraction (left) and fluorescent background subtraction (right).
The autofluorescence from the nose cone and filter leakage have been minimized in the image on the right by using Sub
Fluor Bkg option.
F.7 Adaptive Background Subtraction
Adaptive background subtraction is a simple way to reduce the "instrument fluorescent
background" by fitting and removing the background using the existing image (for
example, the left image in Figure F.16).
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F. Fluorescent Imaging
Unlike the method described in section F.6, Subtracting Instrument Fluorescent
Background, where you acquire an actual instrument fluorescent background image by
removing the fluorescent subject from the imaging chamber to correct the background, the
new method uses software correction. To perform adaptive background subtraction:
• Identify the fluorescent subject in the original image using the photo mask
• The software automatically fits the instrument background to the whole image
using the pixels outside of the subject
• The software subtracts the fitted instrument background from the original image
In most situations, such adaptive software correction works as effectively as the traditional
method except the following cases:
• The subject is dark, making it is difficult to mask the subject using the photo (for
example, experiments that use black well plates)
• The subject occupies most of the FOV (for example, high magnification or
multiple mice in the FOV). As a result, there is not enough information outside the
subject that can be used to help fit the background.
F.8 Subtracting Tissue Autofluorescence Using Background Filters
High levels of tissue autofluorescence can limit the sensitivity of detection of exogenous
fluorophores, particularly in the visible wavelength range from 400 to 700 nm. Even in the
near infrared range, there is still a low level of autofluorescence. Therefore, it is desirable
to be able to subtract the tissue autofluorescence from a fluorescent measurement.
The IVIS® Imaging Systems implement a subtraction method based on the use of blueshifted background filters that emit light at a shorter wavelength (see Table 7.2, page 115).
The objective of the background filters is to excite the tissue autofluorescence without
exciting the fluorophore. The background filter image is subtracted from the primary
excitation filter image using the Image Math tool and the appropriate scale factor, thus
reducing the autofluorescence signal in the primary image data. (For more details, see
Chapter 7, page 115.) The assumption here is that the tissue excitation spectrum is much
broader than the excitation spectrum of the fluorophore of interest and that the spatial
distribution of autofluorescence does not vary much with small shifts in the excitation
wavelength.
Figure F.17 shows an example of this technique using a fluorescent marker. In this
example, 1× 106 HeLa-luc/PKH26 cells were subcutaneously implanted into the left flank
of a 6-8 week old female Nu/nu mouse. Figure F.18 shows the spectrum for HeLa-luc/
PKH26 cells and the autofluorescent excitation spectrum of mouse tissue. It also shows
the passbands for the background filter (DsRed Bkg), the primary excitation filter
(DsRed), and the emission filter (DsRed). Figure F.17 shows the IVIS® images using the
primary excitation filter, the background excitation filer, as well as the autofluorescentcorrected image.
The corrected image was obtained using a background scale factor of 1.4, determined by
taking the ratio of the autofluorescent signals on the scruff of the animal. The numbers
shown in the figures are the peak radiance of the animal background within the region of
interest. In the corrected image, the RMS error is used to quantify the background. The
signal-to-background ratio of the original fluorescent image (DsRed filter) is 6.5. The
ratio increases to 150 in the corrected image, an improvement factor of 23. This
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improvement reduces the minimum number of cells necessary for detection from 1.5× 105
to 6.7× 103.
Figure F.17 Example of the autofluorescent subtraction technique using a background
excitation filter.
a) primary excitation filter (DsRed), b) blue-shifted background excitation filter (DsRed Bkg),
and c) corrected data. The corrected image was obtained by subtracting the scaled
background filter image (multiplied by 0.47) from the primary filter image. The 6-week old
female Nu/nu mouse was injected subcutaneously with 1× 106 HeLa-luc/PKH26 cells in the
left flank.
Figure F.18 Spectral data describing the autofluorescent subtraction technique using a
background filter.
The graph shows the excitation and emission spectrum of PKH26 and the autofluorescent
excitation spectrum of mouse tissue. Also included are the spectral passbands for the blueshifted background filter (DsRed Bkg), the primary excitation filter (DsRed), and the emission
filter used with this dye.
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Appendix G Planar Spectral Imaging
Planar Spectral Imaging Theory . . . . . . . . . . .
Optical Properties . . . . . . . . . . . . . . . . . . .
Luciferase Spectrum . . . . . . . . . . . . . . . . .
An Example of Planar Spectral Imaging . . . . . . .
Optimizing the Precision of Planar Spectral Analysis
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241
241
241
245
The unique spectral signatures of the luciferase emission spectrum and the optical
properties of tissue enable the Living Image software to determine the depth and intensity
of light sources inside a living animal. The planar spectral imaging algorithm relies on a
diffusion model of light propagation in tissue and assumes a point source of light
embedded in a flat surface approximation of the mouse. The algorithm is designed to
provide a fast and robust method to approximate source location and brightness. The
analysis requires two or more single-view images at wavelengths between 560 and 660 nm.
The Diffuse Tomography (DLIT™) algorithm is a more complete and accurate model. It
analyzes images of surface light emission to produce a three-dimensional (3D)
reconstruction of the bioluminescent light sources in a subject. For more details on DLIT
analysis, see Chapter 12, page 151 and Appendix H, page 247.
G.1 Planar Spectral Imaging Theory
An image acquired on an IVIS® Imaging System is a diffuse projection on the surface of
the animal from the bioluminescent sources located deeper inside. Information about the
depth of the bioluminescent cells can help quantify the source brightness and provide
information on the location of the cells.
The Living Image software uses spectroscopic information from a single-view image to
estimate the depth of the bioluminescent cells. The method takes advantage of the fact that
firefly luciferase bioluminescence is emitted from 500 to 700 nm, a region of the spectrum
where there are major contrasts in tissue optical properties (Figure G.1).
In this portion of the spectrum, tissue absorption drops off dramatically between 500-580
nm (green/yellow wavelengths) and 600-750 nm (red wavelengths), due mainly to the
presence hemoglobin. As a result, the bioluminescent signal observed on the surface of the
animal is dependent on both the wavelength and the thickness of the tissue through which
it travels.
The depth and absolute photon flux of a single point source can be determined from two or
more images acquired at different wavelengths using relatively simple analytical
expressions derived from the diffusion model of the propagation of light through tissue.
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G. Planar Spectral Imaging
Figure G.1 Optical Properties of Mouse Tissue and Firefly Luciferase Spectra
The bioluminescent signal from firefly luciferase (right) is emitted from wavelengths of 500-700 nm, which spans a region of
the spectrum where there are major contrasts in the optical properties of mouse tissue (left). The firefly spectrum was
measured at 37°C using PC3M cells.
Diffusion Model of
Light Propagation
Through Tissue
Light propagating through tissue undergoes scattering and absorption. The diffusion
model assumes that scattering is the predominant phenomenon and the reduced scattering
coefficient µ's >> absorption coefficient µa. This is valid mostly for wavelengths in the red
and near infrared part of the spectrum. The model also assumes that the light is produced
by a single point source and that the tissues are optically homogeneous.
Under these conditions, if we model the animal surface as flat and infinite in extent and
integrate the light that is collected over the animal surface, the total integrated intensity
I(λ) is reduced to a relatively simple expression:
I(λ) = SK(λ) exp(-μeff d)
(1)
where S is the absolute total photon flux emitted by the bioluminescent source and d is the
source depth.
The term µeff is the effective attenuation coefficient. It is determined by the tissue
coefficient of absorption (µa) and reduced scattering (µ's) that quantify the two main
phenomena light undergoes in tissue.
The function K(λ) is a more complex expression that is derived from the model and
includes terms that describe the effect of the tissue-air boundary on the light propagation.
Both µeff and the function K are dependent on the wavelength, λ.
Equation 1 shows that if the total integrated intensity (ROI measurement) is measured at
several wavelengths, it is proportional to an exponential function of the product of the
depth and the optical property, µeff. Therefore, the steps to planar spectral image analysis
include:
• Acquire two or more images at different wavelengths.
• Measure the total integrated intensity on each image.
• Fit the measured values to the exponential function of Equation 1.
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The results of the fit are the total flux of the bioluminescence source S and the source depth
d.
G.2 Optical Properties
Planar spectral image analysis requires prior knowledge of the tissue optical properties at
the wavelength used at image acquisition. The two main optical parameters are the:
• Absorption coefficient (µa) that defines the inverse of the mean path before photons
are absorbed by the tissue.
• Reduced scattering coefficient (µ's) that defines the inverse of the mean path before
photons are scattered isotropically in the tissue.
The effective attenuation coefficient (µeff) is a function of the absorption and reduced
scattering coefficients:
µeff = (3µa (µ's + µa))1/2
(2)
Calculation of the function K in Equation 1 requires all three coefficients (µa, µ's, and µeff)
as input. The function K includes a term called the effective reflection coefficient to account
for the reflection of light at the air-tissue boundary due to a mismatch in the index of
refraction. The tissue index of refraction is generally assumed to be close to 1.4.
The model assumes that the tissues are optically homogeneous and the Living Image
software provides several factory set tissue optical property values to choose from.
G.3 Luciferase Spectrum
Analyzing spectrally filtered images requires knowledge of the spectral dependence of
bioluminescent light emission. The luciferase bioluminescence spectrum was measured in
vitro at 37° C and pH≈ 7 in various cell lines. This spectrum is used to normalize the
photon flux values that the software measures at each wavelength.
Source spectra for several reporters are included in the database, including firefly, click
beetle, renilla, and bacteria (Figure G.1).
NOTE
The firefly luciferase spectrum is temperature and pH dependent. The luciferase
spectra included in the software are only valid for measurements performed at 37° C
and pH 7.0-7.5. If you use other temperature or pH conditions for an experiment, the
associated luciferase spectral curve is required for planar spectral image analysis. For
more information on the pH and temperature dependence of the luciferase spectrum,
please contact Xenogen Corporation.
G.4 An Example of Planar Spectral Imaging
Melanoma cells were injected intravenously into the tail vein of nude mice. After 13 days,
metastases developed in the lungs, kidney, and hind limb bone. An image sequence was
acquired on the IVIS® Imaging System 200 Series using filters at six wavelengths from 560
to 660 nm, in 20 nm intervals.
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G. Planar Spectral Imaging
NOTE
When using the 560 nm and 580 nm band pass filters, tissue optics result in a larger
attenuation of light (due mainly to hemoglobin absorption). A longer exposure time is
recommended at these wavelengths.
Figure G.2 shows the metastasis sites. The signals from the lungs and right kidney are well
defined in both animals. However, in the lower back area of the left mouse, the signals are
in close proximity, causing an artifact in the planar spectral analysis.
Figure G.2 Metastatic sites in nude mice.
Mice were imaged 13 days after a tail vein injection of 5x105 B16F10 melanoma cells.
Imaging parameters: high sensitivity binning, f/stop=1, FOV = C (13 cm), exposure time =
120 seconds at 560 and 580 nm, exposure time = 60 seconds at all other wavelengths. This
resulted in signals of ~2000 counts on each image.
To perform the planar spectral analysis, draw a measurement ROI that captures the entire
signal of each site of interest without including a neighboring metastasis (Figure G.3).
After the ROI is defined, start the planar spectral analysis (for more details, see page 121).
The software:
• Measures the total flux inside the ROI on each filtered image.
• Normalizes the data to the luciferase spectrum (Plot of Intensity vs. Lambda,
Figure G.4).
• Fits the normalized data to the analytical expression in Equation 1, page 240
where S = absolute total photon flux emitted by the bioluminescence source and d
= source depth (Plot of Linear Fit Results, Figure G.4)
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Figure G.3 Metastatic site
ROI includes the signal of the right kidney and separates it from other metastatic sites. The
signal coming from the lower back area is spread out due to the presence of two bright spots.
The dimmer signal in the lower bottom right of the image likely originates from the femoral
bone of the animal.
After the analysis is completed,
click a button to display graphical
results.
Figure G.4 Planar spectral analysis results
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G. Planar Spectral Imaging
To estimate the cell count, divide the absolute photon flux by the flux per cell. This is best
determined by making independent in vitro measurements of the cell line used in the
experiment.
The Plot of Linear Fit Results is weighted by the uncertainty of the measured images and
takes into account the uncertainty in the determination of the optical properties. The
precision of the method is largely determined by the known precision of the optical
properties. In most cases, the relative uncertainty in the depth determination is equal to the
relative uncertainty in the optical properties.
An analysis of the dorsal and ventral views of the mouse left lung in Figure G.5 results in
total flux values that are very similar. The measured depth values are also close, indicating
that the cells are distributed about the same distance from the front and back of the animal.
Figure G.5 Planar spectral analysis results
Top: Dorsal view of the left lung, bottom: ventral view of the left lung
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G.5 Optimizing the Precision of Planar Spectral Analysis
The accuracy of the planar spectral analysis is highly dependent on the quality of the:
• Measured data for the firefly luciferase spectrum and the tissue optical properties.
• Fit of the experimentally measured total flux at each wavelength to μeff (effective
attentuation coefficient).
In general, more experimental values produce a better fit of the data. It is particularly
important to be able to extract signals at all wavelengths to optimize the quality of the fit.
If the software detects no signal above the animal background level at 560 nm and 580 nm
(the wavelengths that absorb the most light), the dynamic range of the optical properties is
reduced and with it, the precision of the fit.
If a bioluminescent signal is dim or buried deep in the tissue, it may barely exceed the tissue
autoluminescence at the shorter, more absorbing wavelengths (560 and 580 nm). In this
case, it is recommended that you subtract the tissue autoluminescence from the image data.
(For more details on subtracting tissue autoluminescence, see Appendix E, page 220). It is
also recommended that you inspect all images in the sequence to confirm that the
bioluminescent signal is greater than the tissue autoluminescence. If the bioluminescent
signal does not exceed the tissue autoluminescence at a particular wavelength, do not
include that wavelength in the analysis.
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Appendix H 3D Reconstruction of Light Sources
Determining Surface Topography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247
Algorithm Parameters & Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 252
Diffuse Tomography (DLIT) is a technique that analyzes images of the surface light
emission from a living subject to generate a three-dimensional (3D) reconstruction of
bioluminescent light source distribution inside the subject.
Fluorescent Tomography (FLIT) analyzes images of surface light emission to generate
a 3D reconstruction of fluorescent light source distribution inside the subject.
NOTE
To generate a 3D reconstruction of bioluminescent sources, the Living Image software
requires a photographic image, a structured light image, and bioluminescent images
obtained at two or more wavelength filters from 560-660 nm. To generate a 3D
reconstruction of fluorescent sources, the software requires a structured light and
fluorescent images obtained using the same excitation and emission filters at different
transillumination source positions on the IVIS Spectrum.
To localize and quantify the light sources in a subject, the software:
• Reconstructs the subject surface topography (mesh) from structured light images.
The mesh is defined by a set of connected polygons or surface elements.
radiance (photons/s/cm2/steradian) to the photon density
• Maps the surface
3
(photons/mm ) just beneath the surface of each element of the mesh.
• Divides the interior of the subject into a solid mesh of volume elements or voxels.
Each voxel is considered to contain a point light source at its center that contributes
to the photon density at each surface element.
• Defines equations that relate the source strength of each voxel to the photon density
at each surface element.
• Determines the optimum approximate solution to the system of linear equations to
reconstruct the source strength in each voxel.
H.1 Determining Surface Topography
The software determines the surface topography or mesh from a structured light image.
Parallel laser lines are projected onto the subject to produce a structured light image
(Figure H.1).
NOTE
If the Structure option is chosen in the Control panel, a structured light image is
automatically acquired.
The surface topography of the subject is determined by analyzing the displacement (Δx)
or bending of the laser lines as they pass over the subject. The displacement is defined
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H. 3D Reconstruction of Light Sources
as the difference between where the line should fall on the stage in the absence of the
subject and where it appears in the image due to occlusion by the subject.
Figure H.1 Parallel laser lines projected onto a subject.
Given knowledge of the angle θ, the height of the subject (h) can be determined by analyzing
the displacement, Δx, of the laser lines as they pass over the object.
The parallel lines are projected onto the surface of the subject at an angle (θ) . The angle
is known by instrument calibrations of the distance between the structured light
projector and the optical axis (D) and the distance between the stage and the structured
light projector (l) (Figure H.2).
Figure H.2 Structured light projector and subject.
D and l form two perpendicular sides of a triangle giving:
tan θ = D/l
Together Δx and h comprise a smaller version of this triangle. The height (h) can be
determined from:
h = Δx/tan θ
by measuring the displacement Δx.
The software utilizes fast numerical methods to rapidly evaluate Δx over the entire
image to determine the surface topography. The surface topography determination is
limited to the topside of the object facing the lens.
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Converting Light
Emission to a Photon
Density Map
The input data to the FLIT algorithm for 3D reconstruction of fluorescent light sources
includes:
• A surface mesh that defines the surface of the subject.
• A sequence of images acquired at different transillumination source positions using
the same excitation and emission filter at each position.
The input data to the DLIT algorithm for a 3D reconstruction of bioluminescent light
sources includes:
• A surface mesh that defines the surface of the subject.
• A sequence of two or more images of the light emission from the surface of the
subject acquired at different filter bandwidths (Table A.1)
Table A.1 IVIS System filters for bioluminescence & fluorescence tomography
IVIS® Imaging System
Filters
Bandwidth (nm)
200 Series
6 emission filters, 550-670 nm
20
Spectrum
10 excitation filters, 415-760 nm
20
18 emission filters, 490-850 nm
The IVIS® Imaging System 200 Series and the IVIS Spectrum are absolutely calibrated
so that the electron counts on each CCD pixel can be mapped back to the surface of the
object to produce an absolute value of the surface radiance (photon/s/cm2/steradian)
from each imaged surface element (Figure H.3).
Figure H.3 Light emission from a surface element passes through the lens entrance pupil and is
recorded in the image.
The imaging system collects the light emitted from the surface element at an angle (θe)
(measured with respect to the normal to the surface element) into the solid angle dΩ
subtended by the entrance pupil. The value of the surface radiance L(θe) is directly
related to the photon density ρ (photons/mm3) just inside the surface of the element.
Defining the Linear
Relationship Between
a Source and Photon
Density
The software divides the interior of the subject into a solid mesh of volume elements
(voxels). Each voxel is considered to contain a point light source at its center. The index
i enumerates the set of voxels. Si is the value of the strength (or flux in photons/sec) of
the point source inside the ith voxel. The solid mesh defines a collection of point sources
that approximate the actual source distribution. The accuracy of the approximation is
improved by increasing the density of the solid mesh.
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H. 3D Reconstruction of Light Sources
The reconstruction method is based on the principle that there is an approximately
linear relationship between the source strength in each voxel (Si) and the photon density
(ρ j) at each surface element described by a Green’s function Gij. The photon density at
the jth surface element is the sum of the contributions from all the voxels:
ρj ≅
∑Gij Si
(1)
i
The Green's function contains information about the transport of photons through the
tissue and the effects of the tissue-air boundary. By using a planar boundary
approximation, the Green's function can be calculated analytically as a solution to the
diffusion equation. Having an analytic expression for G allows Equation 1 to be
computed very rapidly.
Finding the Best
Approximate Solution
to the Linear System
Once the Green's functions, Gij, are known, the goal is to solve Equation 1 for the
source strength Si in each voxel. The DLIT algorithm attempts to minimize χ2 (Equation
2) while requiring that the source strength in each voxel is positive (Equation 3).
1- ρ – G S
χ = ∑----σj 2 j ∑ ij i
2
j
2
(2)
i
Si ≥ 0
(3)
A combination of methods called Simplex and Non-Negative Least Squares are used to
find the approximate solution which minimizes χ2. In order to reduce the number of
variables in the problem, the code only uses surface elements with signal above a
certain threshold (minimum radiance) and only keeps the voxels that contribute
significantly to these surface elements.
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Source & Tissue
Properties
DLIT analysis of spectrally filtered images requires knowledge of the spectral
dependence of bioluminescent light emission. Table H.1 shows the factory set source
spectra provided by the software.
NOTE
The source spectra is not an input to the 3D reconstruction of fluorescent sources.
Select a
bioluminescent
source spectrum.
Select a tissue or organ from the
drop-down list. The associated
internal medium index of
refraction is automatically
entered.
Choose the Source Spectrum
from the Plot drop-down list to
display the selected spectrum.
Figure H.4 DLIT 3D reconstruction tools, Properties tab
Table H.1 Source spectra
Source Spectrum
Description
Bacteria
Bacterial luciferase
CB Green
Click beetle green luciferase
CB Red
Click beetle red luciferase
Firefly
Firefly luciferase
XPM-2-LED
LED in the XPM-2 mouse phantom.
hRenilla
Sea pansy (Renilla reniformis) luciferase
NOTE
The firefly luciferase spectrum is dependent on temperature and pH. The data
provided are valid only for measurements performed at 37° C and at pH 7.0-7.5.
Selecting other temperature and pH conditions for a specific experiment requires the
use of the associated spectral curve for the spectral analysis. For more information
about pH and temperature dependence of the luciferase spectrum, please contact
Caliper Life Sciences technical support.
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H. 3D Reconstruction of Light Sources
You can view tissue optical property values (μeff) in the Tissue Properties drop-down
list. The tissue properties are plotted as a function of wavelength. Select the tissue or
organ most representative of the source location. Muscle is a good choice for general
reconstructions in vivo.
NOTE
Default tissue optical properties and source spectrum are specified in the
Preferences box. For more details, see Appendix B, page 201.
H.2 Algorithm Parameters & Options
This section explains the user-modifiable DLIT algorithm parameters and options.
Analyze Tab
Tissue and
source are
specified in the
Active sequence
Select the
acquisition
wavelengths
for the DLIT
analysis.
If DLIT analysis
results are
open, the 3D
tools are
available.
Figure H.5 3D reconstruction tools, Analyze tab, DLIT (left) and FLIT (right)
Wavelengths
For FLIT reconstruction of fluorescent sources, you must specify the transillumination
source positions. It is recommended that you acquire images at a minimum of four
source positions. (All images are acquired using the same excitation and emission
filters.)
For DLIT reconstruction of luminescent sources, you must specify the acquisition
wavelengths for the image sequence. It is generally recommended that you acquire
image data using two to four wavelengths rather than a single wavelength so that more
information is available for the analysis.
Ideally, chose wavelengths or source positions where the signal is well above zero (not
buried in the CCD noise) and the optical property of the medium (μeff) exhibits a large
change. The larger the difference in μeff, the higher the quality of information that the
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wavelength data adds to the analysis. The recommended wavelengths are 580-640 nm for
tissue and 560-620 nm for the Xenogen XPM-2 tissue phantom.
Minimum Radiance
The minimum radiance determines the lower radiance [photons/sec/cm2/sr] threshold of
the data to be used in the DLIT/FLIT analysis.
The software automatically computes a default minimum radiance value and this is the
recommended starting point for an analysis. If too much noise is included in the
analysis, increase the minimum radiance value.
An optimum minimum radiance value can be evaluated by viewing the image data in
photon units (photons/sec/cm2/sr) and adjusting the color bar Min to be above the level
of noise in the image.
Parameters Tab
Figure H.6 3D reconstruction tools, Parameters tab, DLIT (left) and FLIT (right)
Angle Limit
The angle limit refers to the angle between the object surface normal and the optical
axis. The optical axis can be considered to be a line perpendicular to the stage. The
surface normal is a line perpendicular to a plane tangent to the surface point. For
example, in a dorsal view of a mouse, the highest point on its back would have a normal
line perpendicular to the stage. In this case the angle is zero. The side of a mouse
abdomen would have a normal line parallel to the stage, so the angle here would be close
to 90° .
The software uses luminescent image data for surface elements that are less than the
angle limit. The default angle limit setting is 70° for the IVIS® Imaging System 200
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H. 3D Reconstruction of Light Sources
Series or the IVIS Spectrum. For IVIS Spectrum or 200 Series data, if there is
significant signal on the side of the subject, a larger angle of 70-85° can be used.
Kappa Limits (DLIT)
Kappa (κ) is a parameter that is searched during a reconstruction to determine the best
fit to the image data. Small values of kappa tend to favor deeper sources, while large
values favor more shallow sources.
The limits on kappa are minimum of 0.1 and a maximum of 10. The default range for
kappa is 0.5-4. Kappa is doubled at each iteration, so for a selected range of 0.5-4, the
kappa values for each iteration would be 0.5, 1, 2. and 4. Choosing a large range for
kappa produces the most reliable solution, but requires more analysis time.
N Surface (FLIT)
The number of surface intensity points to use in the reconstruction at a given source
position.
N Surface Limits (DLIT)
This is the maximum number of surface intensity points to use in the reconstruction at
a given wavelength. The range is 200 to 800 and the default is 200. The time required
for reconstruction is shortest for smaller values of N (for example, 200). However, a
large N value may give a more accurate result because more data are included in the fit.
Starting Voxel Size (FLIT)
Voxels are the small cubes of space inside a subject, each of which contains a quantity
of fluorescent yield. The FLIT reconstruction begins with large voxels, specified by the
starting voxel size (the length of a voxel cube side in mm). At each iteration, the
algorithm reduces the size of the voxels by a factor of 2 until the optimum solution is
determined.
Starting Voxel Size Limits (DLIT)
Voxels are the small cubes of space inside a subject, each of which contains a light
source (much like a pixel in a 2D image). The DLIT reconstruction begins with large
voxels, specified by the voxel size limit (the length of a side of the voxel cube in mm).
At each iteration, the algorithm reduces the size of the voxel by a factor of two until the
optimum solution is found.
The voxel size limits are a minimum of five and a maximum of 10. The default range
is set to 6-9 mm. A larger range of voxel limits ensures a more reliable solution, but
requires more computational time.
Voxel Size Increment (DLIT)
This is the step increment in voxel size, stepping from the minimum voxel size limit to
the maximum voxel size limit. For example, if the voxel size limit ranges from 6-9 mm,
a voxel size increment = 1 gives four starting voxel sizes (6, 7, 8, and 9 mm).
The default increment of 1 mm is usually adequate, however smaller increments can be
used if you want to sample finer voxel sizes. Smaller increments will significantly
increase the time required for reconstruction.
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Background (FLIT)
Choose this option to take the background fluorescence (for example, autofluorescence
or non-specific probe in circulation) into account. Background fluorescence and
fluorophore emission contribute to the photon density signal at the surface. The
background fluorescence signal is modelled in order to isolate the signal due to the
fluorophore only, where an average homogenous tissue background fluorescence yield
is determined empirically.
Background fluorescence contribution to the photon density at the surface is forwardmodelled. Simulated photon density data due to background at the surface is subtracted
from the measured photon density so that the subsequent photon density used in the fit
consists only of signal that is associated with the fluorophore.
The background option specifies whether or not the background fluorescence should be
fit. This is not necessary for the XFM-2, long wavelength data. It is important when
there is non-specific dye in circulation or a lot of autofluorescence.
Uniform Surface Sampling
If this option is chosen, the surface data for each wavelength will be sampled spatially
uniformly on the signal area. If this option is not chosen, the maximum ‘N surface
elements’ will be sampled for the data. This means that the N brightest surface elements
will be used as data in the reconstruction. Typically, non-uniform sampling is
recommended if there is a single bright source, while uniform sampling is preferred if
there are several scattered sources.
NNLS Optimization + Simplex Optimization (DLIT)
If NNLS Optimization + Simplex option is chosen, the software uses a linear
programming algorithm to seed the solution, followed by the NNLS optimization.
NNLS Weighted Fit
Choose this option to weight the data in the NNLS optimization.
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Appendix I IVIS® Syringe Injection System
Controlling the Infusion Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257
Tracking Infusion in the Maximum vs. Time Graph . . . . . . . . . . . . . . . . . . . . 259
Closing the Infusion Pump Control Panel . . . . . . . . . . . . . . . . . . . . . . . . . . 259
The IVIS Syringe Injection system is designed for use with the IVIS Kinetic Imaging
System. You can control the infusion pump in the Living Image software or manually.
For more details on the setup and manual control of the infusion pump, see the IVIS
Syringe Injection System instructions from Caliper or the PHD 22/2000 Syringe Pump
Series User’s manual from Harvard Apparatus. Both are included on the Living Image
3.2 installation CDROM.
The IVIS Syringe Injection system can be used during kinetic or still image acquisition;
however, subjects must remain immobile.
I.1 Controlling the Infusion Pump
After the IVIS Kinetic imaging system is initialized and locked, you can access the
infusion pump controls.
1. Select Acquisition →Infusion Pump Setup on the menu bar.
— The Infusion Pump control panel appears above the IVIS acquisition control
panel.
NOTE
If you are going to acquire kinetic data, open the infusion pump control panel before
you open the kinetic acquisition control panel. When the kinetic control panel is open,
the Acquisition menu is unavailable.
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I. IVIS® Syringe Injection System
2. Set the volume and flow rate.
3. Make a selection from the Syringe Type drop-down list (the associated syringe
diameter is automatically entered).
To enter a custom syringe:
a. Select Custom from the drop-down list.
b. Click OK in the dialog box that appears.
c. Enter the syringe diameter in the infusion pump control panel.
NOTE
Custom syringe information that is entered in the infusion pump control panel is not
saved to the system.
4. To automatically start the infusion pump after data acquisition begins, choose Auto
Start After and enter the amount of seconds. For example, enter 10 to start infusion
10 seconds after acquisition begins.
To manually start infusion, click Start Now.
5. To automatically stop infusion, choose Auto Stop After Acquisition. To manually
stop infusion at any time, click Stop Now.
If the auto stop option is not chosen and you do not manually stop the pump, the
pump continues to run after acquisition ends.
NOTE
The information in the infusion pump control panel is saved in the click info file. During
acquisition, if you start infusion, then manually stop and restart the infusion, only the
last actual start and stop is saved to the click info file, not the start/stop settings in the
panel.
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I.2 Tracking Infusion in the Maximum vs. Time Graph
During kinetic acquisition, the blue shaded region in the Max vs. Time graph indicates
the infusion period. During acquisition, if you start infusion, then manually stop and
restart infusion, only the last actual start and stop is recorded in the Maximum vs. Time
graph. The graph stops recording infusion when acquisition stops (even though the
pump may not be stopped).
I.3 Closing the Infusion Pump Control Panel
1. Close the kinetic control panel.
2. Click Acquisition →Infusion Pump Setup on the menu bar.
— The check mark is removed and the panel closes.
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I. IVIS® Syringe Injection System
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Appendix J Menu Commands, Tool Bar, & Shortcuts
Figure J.1 Living Image toolbar
Table J.1 Menu bar commands and toolbar buttons
Menu Bar Command
File ➞ Open
File ➞ Browse
File ➞ Browse Biotrue
File ➞ Save
File ➞ Save As
File ➞ Import ➞Organ Atlas
File ➞ Import ➞ DICOM
File ➞ Import ➞ 3D Mesh
File ➞ Import ➞ 3D Volume
File ➞ Export DICOM
File ➞ Export ➞ 3D Mesh
File ➞ Export ➞ 3D Volume
Toolbar
Button
Description
Displays the Open box so that you can select and open an image data file.
Displays the Browse For Folder box so that you can select and an image data
folder. The selected folder is displayed in the Living Image browser.
Opens the Biotrue® CDMS Browser. Note: The browser is only available if the
system includes the Biotrue CDMS option.
Saves (overwrites) the active image data.
Displays the Browse For Folder box so that you can specify a folder in which to
save the image data. The original data is not overwritten.
Opens a dialog box that enables you to import an organ atlas (.atlas).
Opens a dialog box that enables you to import .dcm image data that can be
viewed in the Living Image software.
Opens a dialog box that enables you to import a mesh (.xmh). Note: This
command is only available if an appropriate sequence is active (DLIT or planar
spectral imaging sequence).
Opens a dialog box that enables you to import a source volume (voxels, .xsc).
Note: This command is only available if an appropriate sequence is active (DLIT
or planar spectral imaging sequence).
Opens the Browse for Folder dialog box that enables you to export the active
image data to DICOM format (.dcm).
Opens a dialog box that enables you to save the 3D mesh of the active data in
Open Inventor format (.iv).
Opens a dialog box that enables you to save the voxels from the active data in
Open Inventor format (.iv).
File ➞ Print
Displays the Print box.
File ➞ Print Preview
Displays the Print Preview box that shows what will be printed.
File ➞ Recent Files
File➞ Exit
Shows recently opened data sets. Note: The number of files displayed can be
set in the Preferences box (select Edit ➞Preferences and click the Customize
tab).
Closes the Living Image software.
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J. Menu Commands, Tool Bar, & Shortcuts
Table J.1 Menu bar commands and toolbar buttons (continued)
Menu Bar Command
Edit ➞ Copy
Edit ➞ Image Labels
Edit ➞ Preferences
View ➞ Tool Bar
View ➞ Status Bar
View ➞ Activity Window
View ➞ Tool Palette
View ➞ Activity Window
View ➞ Image Information
View ➞ ROI Properties
View ➞ ROI Measurements
View ➞ Image Layout Window
Toolbar
Button
Description
Copies the active image window to the system clipboard.
Opens the Edit Image Labels dialog box that enables you to edit the label set
information for the active data.
Opens the Preferences box.
Choose this option to display the toolbar.
Choose this option to display the status bar at the bottom of the main window.
Displays the Activity window at the bottom of the main application window. The
Activity window shows a log of the system activity.
Choose this option to display the tool palette.
Choose this option to display the activity bar at the bottom of the main window.
The activity bar lists a history of the recent software activities.
Displays the Image Information box that shows the label set and image
acquisition information for the active data.
Displays the ROI Properties dialog box.
Displays the ROI Measurements table.
Opens the Image Layout window that enables you to paste an image of the
active data in the window.
View ➞ Acquisition Control
Panel
Displays the control panel.
Tools ➞ Image Math for...
Opens the Image Math window for the active data.
Tools ➞ Image Overlay for...
Tools ➞ Colorize xx_SEQ
Tools ➞ Transillumination
Overview
Acquisition ➞ Background ➞
Replace
Opens the Image Overlay window for the active data.
Opens the Colorized View tab for the active sequence. Note: This menu item is
only available if “Show Advanced Options” is selected in the Preferences.
Combines the images of a FLIT sequence into a single image (intensities are
summed) that can be analyzed using tools in the tool palette.
Opens a dialog box that enables you to select an instrument luminescent
background. This background measurement is subtracted from luminescent
images.
Acquisition ➞ Background ➞
View Available Dark Charge
Opens a dialog box that enables you to view the dark charge measurements for
the system.
Acquisition ➞ Background ➞
Clear Available Dark Charge
Opens a dialog box that enables you to remove the dark charge measurements
from the system.
Acquisition ➞ Background ➞
Measure
Opens a dialog box that enables you to acquire a dark charge measurement.
Acquisition ➞ Fluorescent
Background ➞ Add or Replace
Fluorescent Background
Acquisition ➞ Fluorescent
Background ➞ Measure
Fluorescent Background
Acquisition ➞ Fluorescent
Background ➞ Add or Replace
Fluorescent Background
262
Opens a dialog box that enables you to select an instrument fluorescent
background measurement for the active image data. If the Sub Fluor Bkg option
is chosen in the control panel, the background measurement is subtracted from
the image data.
Starts a measurement of the instrument fluorescent background.
Opens a dialog box that enables you to select a fluorescent background
measurement.
Living Image® Software User’s Manual
Table J.1 Menu bar commands and toolbar buttons (continued)
Menu Bar Command
Toolbar
Button
Acquisition ➞ Fluorescent
Background ➞ Clear Available
Fluorescent Background
Acquisition ➞ Fluorescent
Background ➞ View Available
Fluorescent Background
Window ➞ Close
Description
Opens a dialog box that enables you to remove the fluorescent background
measurements from the system.
Opens a dialog box that displays the fluorescent background measurements for
the system. If a fluorescent background is selected, the Sub Fluor Bkg option
appears in the control panel. Choose the Sub Fluor Bkg option to subtract the
user-specified background measurement from the image data.
Closes the active image window.
Window ➞ Close All
Window ➞ Cascade
Window ➞ Tile
Closes all image windows.
Organizes the open image windows in a cascade arrangement (see page 59).
Organizes the open image windows in a tiled arrangement (see page 58).
Window ➞ 1. xx
A list of the open data. Select the data of interest to it the active window and
display it on top of all other open windows.
Window ➞ 2. xx
Window ➞ etc.
Window ➞ Other Windows ➞
Browser Window
If the Living Image browser is open, makes it the active window and displays it
on top of all other open windows.
Help ➞ User Guide
Displays the online help.
Help ➞ About Living Image
Displays the online help index.
Click this button, then click an item in the user interface to display information
about the item.
Table J.2 Keyboard shortcuts
Keys
Shortcut Description
Ctrl + B
Opens the Living Image browser.
Ctrl + C
Copies the active image to the system clipboard.
Ctrl + D
Arranges open windows in a cascade.
Ctrl + O
Displays a dialog box that enables you to open data.
Ctrl + P
Open the Print dialog box.
Ctrl + S
Saves the active file or window.
Ctrl + T
Tiles the open windows.
Ctrl + W
Closes the active window.
Shift + F1
Changes the mouse pointer to the “What’s This” tool
.
Click this button, then click an item in the user-interface to display information about the item.
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Index
Numerics
3D fluorescent sources 156–157
3D image
rotate or move 166
3D luminescent sources 152–155
3D perspective 169
3D reconstruction
fluorescent sources 156–157
parameters & options 252–255
3D reconstruction results 158–160
3D tools 162–187
Animation tab 182–183
Mesh tab 170–171
Organs tab 175–176
Volume tab 172–173
A
accumulate signal 38, 40
acquire
image sequence 31–32
kinetic data 37
single bioluminescence image 15–18
single fluorescence image (epi-illumination) 18–19
single fluorescence image (trans-illumination)
19–22
adaptive fluorescent background subtraction 235
adjusting image appearance 63
angle limit 253
animation 182–187
custom 185–186
edit an animation setup 186–187
preset 184–185
auto exposure feature 12
autofluorescence 91, 229
miscellaneous material 231–233
See tissue autofluorescence.
subtract using background filters 236–237
well plate 230–231
autoluminescence 91
automatically draw ROIs 88–89
average background ROI 82, 91
B
background
adaptive fluorescent background subtraction 235
fluorescent 229–235
light on sample 218–220
tissue autofluorescence 236–237
background light
from sample 220–222
on sample 218–220
background-corrected signal 91–93
band gap 226
bandpass filter 225
binning 66, 67, 206–208
bioluminescence image 15–18
browse image data 45–46
browser 46
C
Caliper Corporation
technical support 3
cascade images 58
color table 211
colorize data 74–75
composite image 112–115
control panel 12, 191–194
conventions 2
copy
ROI measurements 107
correction/filtering tools
binning 66
cosmic correction 66
dark background subtraction 66
flat field correction 66
smoothing 67
cosmic correction 66
cosmic ray corrections 216
counts 213
crop box 73
D
dark background subtraction 66
dark charge 218
dark current 217
data
graphic image 211
scientific image 211
265
Index
detection efficiency 205
detection sensitivity
adjusting the lens aperture 205
exposure time 206
field of view 206
DICOM file 33, 35
size limit 43
diffusion model 240
display modes 56
display units
counts 213
efficiency 215
photons 214
DLIT
troubleshooting 189
DLIT results 158–160
manage 187
drift correction 217
E
edit
image sequence 29–31
edit image sequence 52–53
efficiency 215, 225, 228–229
electronic background
dark charge 218
dark current 217
drift 217
read bias 217
EM gain 40
export image data 35
exposure time 206
F
f/stop
fluorescent imaging 228
field of view 206
filter
bandpass 225
fluorescent 226
filter spectra 225
flat field correction 66
flat fielding 216
FLIT
troubleshooting 189
FLIT results 158–160
manage 187
266
fluorescence
adaptive background subtraction 235
reconstruct 3D sources 156–157
fluorescence efficiency 228–229
fluorescence image (epi-illumination) 18–19
fluorescence image (trans-illumination) 19–22
fluorescence imaging components 223–225
fluorescent filters 226
fluorescent imaging
efficiency 225
f/stop 228
normalization 225
focus manually 34
FOV settings 194
G
graphic image data 211
H
High Reflectance Hemisphere 219
histogram 70
I
image
adjusting appearance 63
cascade 58
correct or filter 66–67
correcting/filtering tools 66–67
histogram 70
image window 55–56
information 59
label 61
line profile 71
magnify or pan 65
measurements 72
pixel data 69
tag 58
thumbnails 51
tile 58
image analysis tools 8
image data
browse 45–46
colorize 74–75
export 35
open 47–49
save manually 34
image information 67–68
Living Image® Software User’s Manual
image layout window 62–63
image math 112–115
image overlay tool 118–120
image sequence 51–53
acquire 31–32
analyses 8
application-specific 23
create from individual images 53–54
edit 29–31, 52–53
imaging wizard 24–26
manual setup 26–28
image window 17
3D perspective 169
display modes 56
image window (single image) 55–56
imaging & image analysis
example workflow 7
overview 5–8
imaging wizard 24–26
index of refraction 159
information about an image 59
infusion pump 257
infusion syringe injection system
control panel 258
infusion pump 257
initialization
See system initialization.
instrument fluorescent background
background
instrument fluorescent background 235
IVIS Imaging System
fluorescence imaging components 223–225
K
kappa 159
kappa limits 159, 254
kinetic
acquisition settings 39
acquisition window 38
kinetic data
acquire 37
save 43, 44
view and edit 42
kinetic ROI
plot 95
draw 95, 94
L
lens aperture 205
line profile 71
Living Image browser 46
Living Image software
starting 9
luciferase spectrum 241
luminescence
reconstruct 3D sources 152–155
M
magnify image 65
manual
focusing 34
save data 34
manual conventions 2
maximum vs time graph
tracking infusion 259
maximum vs. time graph 41
measurement ROI
automatically draw 88–89
measurement ROIs 82, 84–89
free draw 90
measurements 72
menu commands 261
mesh
drawing style 167
lighting style 167
miscellaneous material autofluorescence 231–233
multiple reporters per photograph 118–120
N
N surface limits 159, 254
NNLS
optimization 159, 255
weighted fit 159, 255
normalization 225
O
open image data 47–49
optical density 226
optical properties for planar spectral imaging 241
organ atlas 181
organs 176–180
overlay 212
overlaying images 118–120
overview
267
Index
imaging & image analysis 5–8
P
pan image 65
PCA biplot 136
PCA explained variance 137
photon density 160
photon density map
measured 160
simulated 160
photon radiance 214
photons 214
pixel 211
pixel data 69
planar spectral analysis
optimizing precision 245
planar spectral image analysis 121–123
planar spectral imaging 239–245
diffusion model 240
intensity graph 125
linear fit graph 125
luciferase spectrum 241
optical properties 241
results 124
tools 123–124
point source fitting 143–147
results 148–149
tools 143–146
preferences 195–203
pseudocolor image 211
R
radiance
photon 214
radiance units 214
read bias 217
reconstruct 3D fluorescent sources 156–157
reconstruct 3D luminescent sources 152–155
reduced Chi2 159
ROI 81
automatically draw 88–89
background-corrected signal 91–93
delete 105
edit dimensions 101
edit position 101
free draw 90
managing 97
268
manually draw 86–87
measurement ROI
free draw 90
measurement ROIs 84–89
Measurements table 86
move 100
move or edit label 103
quick guide 84
ROI line 102
save 104
subject 90
tools 82–83
ROI (kinetic)
quick guide 94, 95
ROI Measurements table 106–108
configure 108–110
copy or export 110
ROI properties 97–99
ROI types
average background 82, 91
measurement 82
subject 82
S
save
data manually 34
ROI 104
kinetic data 44, 43
scientific image data 211
segment 29
smoothing 67, 208
source spectrum 160
spectral imaging
See planar spectral imaging.
spectral unmixing 127–130
options 134–135
parameters 132–133
PCA biplot 136
PCA explained variance 137
results 131–132
starting the software 9
starting the system
See system initialization.
steradian 214
subject ROI 82, 90
surface topography 139–140
syringe injection system 257–259
Living Image® Software User’s Manual
system
FOV 194
initialization 11
optics autofluorescence 235
temperature 11
X
x,y coordinates 174
T
tag an image 58
technical support 3
temperature 11
threshold angle 159
tile images 58
tissue autofluorescence 236–237
eliminate by spectral unmixing 127–130
subtracting with background filters 115–117
tissue properties 160
tool palette 50
3D tools 162–187
correcting/filtering 66–67
image information 67–68
point source fitting 143–146
ROI tools 82
toolbar 261
total source flux 158
transillumination overview 76
troubleshooting guide 189
U
uniform surface sampling 159, 255
units
See display units.
user preferences 195–203
V
voxel 173, 249
size increment 254
size increments 159
size limits 159, 254
vsize
final 159
starting 159
W
well plate autofluorescence 230–231
269
Index
270
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