High-performance electronics system for a small animal PET scanner based on sub-millimeter pitch crystal arrays

Abstract Small animal positron emission tomography (PET) is an essential tool for in-vivo preclinical research and is constantly evolving towards better spatial resolution and higher sensitivity. Accordingly, electronics for small animal PET systems face the challenges of achieving higher intrinsic resolution, faster data processing, and higher integration. In this paper, to read out the signals of a scanner composed of 20 × 20 LYSO arrays with a pitch of 0.8 mm and a thickness of 20 mm, we designed a high-performance readout electronics system and evaluated its performance. The electronics test results show that the charge measurement resolution is better than 0.5% and the timing resolution is better than 200 ps under a typical signal input amplitude of 0.8 V. Preliminary tests with detectors were also carried out under a room temperature environment. Combined the developed electroncs with dual-ended readout PET detectors, the results show that all LYSO elements in flood histogram are clearly identified with an average distance-to-width ratio (DWR) of 4.42, and the energy resolution and the coincidence time resolution are 22.17% and 3.91 ns, respectively.