Comparison of Timing Measurement Methods of Dual-Ended Readout Scintillator Array PET Detectors

• Published in: IEEE transactions on radiation and plasma medical sciences 2024-07, Vol.8 (6), p.607-617
• Main Authors: Niu, Ming, Kuang, Zhonghua, Wang, Xiaohui, Ren, Ning, Sang, Ziru, Sun, Tao, Liu, Zheng, Hu, Zhanli, Gu, Zheng, Yang, Yongfeng
• Format: Article
• Language: English
• Subjects: Application specific integrated circuits; Arrays; Barite; Barium; Barium sulfate; Crystals; Detectors; Dual-ended readout; Energy resolution; Integrated circuits; Lutetium; Measurement methods; PET detector; PETsys application specific integrated circuit (ASIC); Photodetectors; Photomultiplier tubes; Pixels; Positron emission; Positron emission tomography; Scintillation counters; Scintillators; Sensors; Spatial discrimination; Spatial resolution; Time measurement; Timing; timing measurement; timing resolution; Yttrium
• ISSN: 2469-7311; 2469-7303
• DOI: 10.1109/TRPMS.2024.3382990

The main focus of this work is to compare different timing measurement methods of individual silicon photomultiplier (SiPM) arrays and dual-ended readout PET detectors. Two lutetium yttrium oxyorthosilicate (LYSO) crystal arrays with 3.10\times 3.10\times 20 - {\mathrm { mm}}^{3} crystals, enhanced specular reflector (ESR), and barium sulfate (BaSO4) reflector and one LYSO crystal array with 1.88\times 1.88\times 20 - {\mathrm { mm}}^{3} crystals and \rm BaSO_{4} reflector with dual-ended read out by 8\times 8 SiPM arrays of 3\times 3 - {\mathrm { mm}}^{2} active pixel area were measured. Signals of the SiPM arrays were processed individually using 64 channel PETsys TOFPET2 application specific integrated circuits designed for time-of-flight PET applications. For the SiPM arrays, an energy square-weighted average timing method using the timings of the fastest 2 SiPM pixels was found to provide the best-coincidence timing resolutions (CTRs). For the dual-ended readout detectors, the method of using the energy-weighted average timings of the two SiPM arrays provided the best CTR of 234 ps for the detector using 3.10\times 3.10\times 20 - {\mathrm { mm}}^{3} crystals and ESR reflector, 239 ps for the detector using 3.10\times 3.10\times 20 - {\mathrm { mm}}^{3} crystals and \rm BaSO_{4} reflector, and 275 ps for the detector using 1.88\times 1.88\times 20 - {\mathrm { mm}}^{3} crystals and