Preliminary Optimized Design of a High-resolution PET Detector with a 0.5 mm Crystal Size

The purpose of this study is to develop a PET detector with a 0.5 mm crystal size for high-resolution preclinical PET imaging. The methods to improve the decoding performances of the detectors, including the wedge-shaped light guides with different thicknesses, different methods to suppress the dark count noises in the SiPMs and different methods to calculate the flood maps, were investigated. The experimental results show that the PET detector developed in this study achieved an extraordinary decoding performance. The ratio of background “noise” in the flood map to the total events is about 40%. The simulation study shows that the intrinsic intra-crystal Compton scatters contribute to 30.32% of the background “noise”. Thus, the optical design of the detector and the electronics and algorithms to generate the flood maps only introduced 10% the background “noise”. We are currently constructing a high-resolution preclinical PET imager using 12 detectors.