ANALYTIC TREATMENT OF RESOLUTION PRECISION IN ELECTRONICALLY COLLIMATED SPECT IMAGING INVOLVING MULTIPLE-INTERACTION GAMMA-RAYS

The widely applied single-interaction analytic expression characterizi ng the energy resolution component of the angular resolution precision for an electronically collimated point source is extended to include multiple-interaction Compton scatter sequences as well as sequences te rminated by photoelectric absorption. The analytic formulation is deve loped using the statistical variance of the mean for components compri sing composite, multivariate resolution precision estimators. It is de monstrated that enhanced resolution precision in the incident interact ion scatter angle is attained when use is made of information from mul tiple interactions. An improvement in the resolution precision of up t o approximately 40% is observed for triple Compton scatter. Comparison of the analytic estimates with Monte Carlo/chi-square results shows g ood agreement.