A Monte Carlo study of a high resolution $\gamma$-detector for small organ imaging in Nuclear Medicine

A reliable Monte Carlo simulation study is of significance importance to evaluate the performance of a gamma-ray detector and the search for compromises between spatial resolution, sensitivity and energy resolution. The development of a simulation package for a new compact gamma camera based on GEANT3 is described in this report. This simulation takes into account the interaction of gamma-rays in the crystal, the production and transport of scintillation photons and allows an accurate radiation transport description of photon attenuation in high-Z collimators, for SPECT applications. In order to achieve the best setup configuration different detector arrangements were explored, namely different scintillation crystals, coatings, reflector properties and polishing types. The conventional detector system, based on PMT light readout, was compared with an HPD system. Different collimators were studied for high resolution applications with compact gamma-cameras.