Effects of varying physical parameters of a PET system on the accuracy of radioactivity quantitation in vivo.
The accuracy of quantitation of radioactivity by positron emission tomography (PET) is dependent on design parameters which differ among the PET-cameras in use today. Using a high resolution PET camera (Scanditronix PC 4096-15WB) we have simulated various of these parametric design differences such as xy- and z-resolution, slice thickness, methods of scatter and attenuation correction. The quantitation of actual patient data differed by up to 40% for both static and dynamic data when single parameters were varied to fit cameras of preexisting and recent design. For example, we found that cortical FDG data are 15% lower for 11 mm image resolution than for 5.5 mm image resolution, and striatal uptake of a D2-receptor-ligand decreases by 25% when the slice thickness is 14 mm instead of 7 mm. In general, the errors due to the single effects studied here are expected to be cumulative, leading to an even greater discrepancy in the overall performance of older PET cameras when compared to those of recent design.
Herzog
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Institute of Medicine, Research Center Jülich, Germany.
Rota Kops
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Schmid
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Feinendegen
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LE
D001921:Brain / Q000000981:diagnostic imaging / Q000378:metabolism; D003847:Deoxyglucose / Q000031:analogs & derivatives / Q000378:metabolism; D019788:Fluorodeoxyglucose F18; D015902:Gamma Cameras; D006801:Humans; D007091:Image Processing, Computer-Assisted; D011851:Radioactivity; D014055:Tomography, Emission-Computed / Q000295:instrumentation*
D019788:Fluorodeoxyglucose F18; D003847:Deoxyglucose