Mf. Kijewski et al., Effects of SPECT collimation and system geometry on classification tasks related to Parkinson's disease, IEEE NUCL S, 48(3), 2001, pp. 734-738
We assessed the potential performance of three commercial SPECT systems in
simulated, but realistic imaging tasks related to the diagnosis and managem
ent of Parkinson's disease (PD). Images of I-123 altropane activity distrib
utions in normal and PD brains were modeled assuming values from the litera
ture for striatal sizes and activity concentrations, as well as for nonspec
ific activity. Imaging characteristics of the three systems were determined
by phantom studies. The expected distributions of estimates of activity co
ncentration and striatal volume were based on covariance matrices determine
d by the Cramer-Rao lower bounds calculated for a simultaneous estimation o
f these two parameters, as well as background activity concentration. Poten
tial performance in several binary classification tasks was assessed by fit
ting ROC curves to simulated likelihood ratios for 5000 "subjects" in each
category. For all conditions studied, ROC areas were similar for the higher
resolution instruments and lower for the lower resolution system. These re
sults imply a diagnostic advantage for higher resolution systems in imaging
tasks related to PD.