Performance Results of BGO Block Detectors Based on Flat Panel PS-PMT for PET

We have developed a new detector composed of a 20times20 array of 2times2times20 mm³ Bi₄Ge₃O₁₂ (BGO) scintillators and a novel flat panel position sensitive photomultiplier tube(FP-PS-PMT) - Hamamatsu R8400-00-M256. The performance of the block detector was evaluated in terms of applicability to positron emission tomography (PET). The energy resolution was about 23% FWHM for 511 keV gamma-rays. The spatial resolution of the detector was evaluated by measuring the detector response functions (DRFs) for each BGO segment and by measuring the coincidence response functions (CRFs). The average FWHM values of the DRFs were 2.0 mm. For the CRFs performance, the average FWHM values were 2.82 mm at 0deg and 5.20 mm at 30deg.