DEVELOPMENT OF CONTINUOUS DETECTORS FOR A HIGH-RESOLUTION ANIMAL PET SYSTEM

We propose a design for a high resolution, gamma-camera style detector that is suitable for use in a positron emission tomograph dedicated t o small animal research. Through Monte Carlo simulation we modeled the performance of a detector composed of one 76.2 x 76.2 x 8 mm thick LS O crystal coupled to a 3 '' square position sensitive photomultiplier tube (PS-PMT). We investigated the effect of optical coupling compound s, surface treatment and depth of interaction on the quantity (efficie ncy) and distribution (spread) of scintillation photons reaching the p hotocathode. We also investigated linearization of the position respon se. We propose a PET system consisting of fourteen of these detectors in 2 rings, yielding a 16 cm diameter by 15 cm long tomograph. It woul d operate in 3-D mode subtending a 68% solid angle to the center. The expected spatial resolution is less than or equal to 2 mm, with a syst em efficiency of similar to 10% at the center (200 keV lower threshold ) and a singles count rate capability of approximately 10(6) cps per d etector.