Assessment of accuracy of PET utilizing a 3-D phantom to simulate the activity distribution of [18F]fluorodeoxyglucose uptake in the human brain.
A three-dimensional brain phantom has been developed to simulate the activity distributions found in human brain studies currently employed in positron emission tomography (PET). The phantom has a single contiguous chamber and utilizes thin layers of lucite to provide apparent relative concentrations of 5, 1, and 0 for gray matter, white matter, and CSF structures, respectively. The phantom and an ideal image set were created from the same set of data. Thus, the user has a basis for comparing measured images with an ideal set that allows a quantitative evaluation of errors in PET studies with an activity distribution similar to that found in patients. The phantom was employed in a study of the effect of deadtime and scatter on accuracy in quantitation on a current PET system. Deadtime correction factors were found to be significant (1.1-2.5) at count rates found in clinical studies. Deadtime correction techniques were found to be accurate to within 5%. Scatter in emission and attenuation correction data consistently caused 5-15% errors in quantitation, whereas correction for scatter in both types of data reduced errors in accuracy to less than 5%.
Hoffman
E J
EJ
Division of Nuclear Medicine and Biophysics, UCLA School of Medicine 90024.
Cutler
P D
PD
Guerrero
T M
TM
Digby
W M
WM
Mazziotta
J C
JC
D001921:Brain / Q000000981:diagnostic imaging* / Q000378:metabolism; D003847:Deoxyglucose / Q000031:analogs & derivatives* / Q000378:metabolism / Q000493:pharmacokinetics; D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008954:Models, Biological; D008961:Models, Structural; D014018:Tissue Distribution; D014055:Tomography, Emission-Computed / Q000592:standards*
D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D003847:Deoxyglucose