DETECTOR, SHIELDING AND GEOMETRIC DESIGN FACTORS FOR A HIGH-RESOLUTION PET SYSTEM

We evaluated the resolution, efficiency and scatter rejection on a new high resolution PET system designed for animal studies which is based on a 2-D modular detector system. A digital positioning system was evaluated by testing different encoding methods. Tungsten inter-plane septa of different thicknesses and geometries were evaluated by Monte Carlo simulations and experiments. The detector system consists of a 6×8 array of BGO crystals coupled to 2 dual photomultiplier tubes (PMTs). The crystals are 3.5 mm wide with 4 mm spacing transaxially and are 6.25 mm long with 6.75 mm spacing axially. PMT outputs are digitized and Anger camera type logic is used to determine the X and Y location of the scintillation event. Data is then sorted into the appropriate detector using a column look up table then column dependent row look up tables. The digital nature of the data collection system, which allows optimization of crystal identification, was found to be essential to the performance of the detector system. Copyright © 1990 by The Institute of Electrical and Electronics Engineers, Inc.