A SIMULATION TO MODEL POSITION ENCODING MULTICRYSTAL PET DETECTORS

We have developed a simulation to model position encoding multicrystal detectors for positron emission tomography. The simulation is designe d to treat the interactions of energetic photons in a scintillator, th e geometry of the multicrystal array, as well as the propagation and d etection of individual scintillation photons. The simulation is tested with a model of the EXACT AR PLUS block detector manufactured by Siem ens-CTI, Position and energy responses derived from the simulation are compared to measured ones. Line spread functions, for four columns of crystals, are reproduced with an accuracy of +/- 0.5 mm, The crystal- by-crystal photopeak pulse heights and FWHM's are also predicted withi n a range of +/- 14%, and (-6)(+9)%, respectively.