Avalanche photodiodes in scintillation detection for high resolution PET

Several scintillation detectors containing LSO, YAP, and BGO crystals coupled to 5 mm in diameter beveled-edge large area avalanche photodiodes (LAAPD) were studied. These configurations were chosen to address requirements of high-resolution positron emission tomography (PET). The number of electron-hole pairs, the energy resolution for 511 keV /spl gamma/-rays, detection efficiency, and timing properties were measured in various configurations to establish best operating conditions for these detectors. The obtained results point towards a possibility of replacing photomultiplier tubes (PMT) in PET with LAAPDs, leading potentially to more compact, reliable, and accurate systems.