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In case anyone is interested, I never did hear back from anyone with AAPM TG 126 about where these values came from. Doing my own digging, here is what I found: To find out your system's Sensitivity and Activity Correction Factor ranges: open</div>
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In case anyone is interested, I never did hear back from anyone with AAPM TG 126 about where these values came from.</div>
<div style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 11pt; color: rgb(0, 0, 0);" class="elementToProof">
<br>
</div>
<div style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 11pt; color: rgb(0, 0, 0);" class="elementToProof">
Doing my own digging, here is what I found:</div>
<div style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 11pt; color: rgb(0, 0, 0);" class="elementToProof">
To find out your system's Sensitivity and Activity Correction Factor ranges:</div>
<ol style="margin-top: 0px; margin-bottom: 0px; list-style-type: decimal;" data-editing-info="{"applyListStyleFromLevel":false,"orderedStyleType":1}" start="1">
<li style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 11pt; color: rgb(0, 0, 0);">
<div role="presentation" class="elementToProof">open a unix shell</div>
</li><li style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 11pt; color: rgb(0, 0, 0);">
<div role="presentation">cd /usr/g/PET/systemConfig/local</div>
</li><li style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 11pt; color: rgb(0, 0, 0);">
<div role="presentation">more cal.cfg (this is actually a symlink to a file that matches your system configuration)</div>
</li></ol>
<div style="margin-left: 40px; font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 11pt; color: rgb(0, 0, 0);" class="elementToProof">
You can also grep for any of these strings (the asterisks aren't wild cards, it's GE's delimiter for the config file):</div>
<div style="margin-left: 40px; font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 11pt; color: rgb(0, 0, 0);" class="elementToProof">
wcc*minActivity</div>
<div style="margin-left: 40px; font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 11pt; color: rgb(0, 0, 0);" class="elementToProof">
wcc*minActivity</div>
<div style="margin-left: 40px; font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 11pt; color: rgb(0, 0, 0);" class="elementToProof">
wcc*min2DActivityFac</div>
<div style="margin-left: 40px; font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 11pt; color: rgb(0, 0, 0);" class="elementToProof">
wcc*max2DActivityFac</div>
<div style="margin-left: 40px; font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 11pt; color: rgb(0, 0, 0);" class="elementToProof">
wcc*min3DActivityFac</div>
<div style="margin-left: 40px; font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 11pt; color: rgb(0, 0, 0);" class="elementToProof">
wcc*max3DActivityFac</div>
<div style="margin-left: 40px; font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 11pt; color: rgb(0, 0, 0);" class="elementToProof">
wcc*minSensitivity</div>
<div style="margin-left: 40px; font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 11pt; color: rgb(0, 0, 0);" class="elementToProof">
wcc*maxSensitivity</div>
<div style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 11pt; color: rgb(0, 0, 0);" class="elementToProof">
The console contains a collection of config files for different models and detector configurations. I grep'ped for a few of the above strings for Activity Correction Factor ranges, and have attached a picture of the output.</div>
<div style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 11pt; color: rgb(0, 0, 0);" class="elementToProof">
AAPM TG 126 simply lists the GE Vendor Limit Mean (Range) of 2.0-12.0, but that is for just one detector model. Other acceptable ranges include [0.01,5.16] or [1.95,7.80].</div>
<div style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 11pt; color: rgb(0, 0, 0);" class="elementToProof">
<br>
</div>
<div style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 11pt; color: rgb(0, 0, 0);" class="elementToProof">
To see the values of the Sensitivity and Activity Correction Factors</div>
<ol style="margin-top: 0px; margin-bottom: 0px; list-style-type: decimal;" data-editing-info="{"applyListStyleFromLevel":false,"orderedStyleType":1}" start="1">
<li style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 11pt; color: rgb(0, 0, 0);">
<div role="presentation" class="elementToProof">open a unix shell</div>
</li><li style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 11pt; color: rgb(0, 0, 0);">
<div role="presentation">cd /usr/PET/release/dragon/bin/linux2</div>
</li><li style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 11pt; color: rgb(0, 0, 0);">
<div role="presentation">stardWcc 3d</div>
</li><li style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 11pt; color: rgb(0, 0, 0);">
<div role="presentation" class="elementToProof">The 3D Sensitivity and Activity Correction Image Sets browser window will display.</div>
</li><li style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 11pt; color: rgb(0, 0, 0);">
<div role="presentation">Select an image series.</div>
</li><li style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 11pt; color: rgb(0, 0, 0);">
<div role="presentation" class="elementToProof">Click OK.</div>
</li></ol>
<div style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 11pt; color: rgb(0, 0, 0);">
The shell will update with text from WCC Senstivity and Activity </div>
<div class="elementToProof" id="Signature">
<div style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 11pt; color: rgb(0, 0, 0);" class="elementToProof">
<br>
</div>
<div style="font-family: Calibri, Helvetica, sans-serif; font-size: 11pt;" class="elementToProof">
Best,</div>
<div style="font-family: Calibri, Helvetica, sans-serif; font-size: 11pt;" class="elementToProof">
Josh M. Wilson, PhD</div>
<div class="elementToProof"><br>
</div>
<div class="elementToProof"><span style="font-family: Calibri, Helvetica, sans-serif; font-size: 11pt; color: rgb(0, 0, 0);">Duke University Health System</span><br>
</div>
<div style="margin-left: 40px; font-family: Calibri, Helvetica, sans-serif; font-size: 11pt;" class="elementToProof">
Radiation Physicist, Clinical Imaging Physics Group</div>
<div style="font-family: Calibri, Helvetica, sans-serif; font-size: 11pt;" class="elementToProof">
<span style="color: rgb(0, 0, 0);">Duke University, School of Medicine</span><br>
</div>
<div style="margin-left: 40px; font-family: Calibri, Helvetica, sans-serif; font-size: 11pt;" class="elementToProof">
Director, Duke Imaging Physics Residency Program</div>
<div style="margin-left: 40px; font-family: Calibri, Helvetica, sans-serif; font-size: 11pt;" class="elementToProof">
Assistant Professor, Department of Radiology</div>
<div style="font-family: Calibri, Helvetica, sans-serif; font-size: 11pt; color: rgb(0, 0, 0);" class="elementToProof">
Duke University, Graduate School</div>
<div style="margin-left: 40px; font-family: Calibri, Helvetica, sans-serif; font-size: 11pt; color: rgb(0, 0, 0);" class="elementToProof">
Faculty, Medical Physics Graduate Program</div>
</div>
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<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" style="font-size:11pt" color="#000000"><b>From:</b> Intl_dxmedphys_wd_osu_list <intl_dxmedphys_wd_osu_list-bounces@lists.osu.edu> on behalf of Josh M Wilson via Intl_dxmedphys_wd_osu_list <intl_dxmedphys_wd_osu_list@lists.osu.edu><br>
<b>Sent:</b> Tuesday, March 3, 2026 10:02 AM<br>
<b>To:</b> International Diagnostic Medical Physics List <intl_dxmedphys_wd_osu_list@lists.osu.edu><br>
<b>Subject:</b> [Intl_DxMedPhys] AAPM TG 126 reference for Vendor's sensitivity values?</font>
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In AAPM TG 126, "PET/CT Acceptance Testing and Quality Assurance", in the Sensitivity section, there are a couple of methods and vendors described. There is a table that lists vendor ranges, but I'm not sure where these values come</div>
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<br>
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In AAPM TG 126, "PET/CT Acceptance Testing and Quality Assurance", in the Sensitivity section, there are a couple of methods and vendors described. There is a table that lists vendor ranges, but I'm not sure where these values come from. Does anyone know? I'm
especially interested in GE.</div>
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<img size="29967" style="max-width:491px" data-outlook-trace="F:2|T:2" src="cid:dd2f62a9-257b-4b11-9ca2-04c307f1851a"></div>
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<br>
</div>
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Further, in Appendix A.2, the first example for GE states:</div>
<div class="x_elementToProof" style="font-family:Aptos,Aptos_EmbeddedFont,Aptos_MSFontService,Calibri,Helvetica,sans-serif; font-size:11pt; color:rgb(0,0,0)">
"The activity correction factor should be displayed at the bottom of the graph (Figure A.5). GE specifies that this factor should be within 2.0 and 12.0, while the sensitivity correction factors shown on the graph per slice should be within 0.8 and 1.5."</div>
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But I don't know where those values come from. Interestingly enough, Figure A.5 shows a GE IQ scanner as an example and the highlighted activity correction factor is "1.07131" which is specifically outside the (2.0,12.0) range.</div>
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<br>
</div>
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<br>
</div>
<div class="x_elementToProof" style="font-family:Calibri,Helvetica,sans-serif; font-size:11pt">
Best,</div>
<div class="x_elementToProof" style="font-family:Calibri,Helvetica,sans-serif; font-size:11pt">
Josh M. Wilson, PhD</div>
<div class="x_elementToProof"><br>
</div>
<div class="x_elementToProof"><span style="font-family:Calibri,Helvetica,sans-serif; font-size:11pt; color:rgb(0,0,0)">Duke University Health System</span><br>
</div>
<div class="x_elementToProof" style="margin-left:40px; font-family:Calibri,Helvetica,sans-serif; font-size:11pt">
Radiation Physicist, Clinical Imaging Physics Group</div>
<div class="x_elementToProof" style="font-family:Calibri,Helvetica,sans-serif; font-size:11pt">
<span style="color:rgb(0,0,0)">Duke University, School of Medicine</span><br>
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<div class="x_elementToProof" style="margin-left:40px; font-family:Calibri,Helvetica,sans-serif; font-size:11pt">
Director, Duke Imaging Physics Residency Program</div>
<div class="x_elementToProof" style="margin-left:40px; font-family:Calibri,Helvetica,sans-serif; font-size:11pt">
Assistant Professor, Department of Radiology</div>
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Duke University, Graduate School</div>
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Faculty, Medical Physics Graduate Program</div>
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