TOF-PET探测器定时性能初步研究

Pilot Study of Timing Performance for Time-of-Flight Positron Emission Tomography Detector

摘要: 本工作采用LYSO晶体阵列和平板型位置灵敏光电倍增管H8500对TOF-PET探测器进行了初步设计，能分辨3.2 mm×3.2 mm的晶体阵列。与BaF₂探测器组成时间谱仪，测量正电子湮没射线的瞬发时间谱，得到379 ps的符合时间分辨率。根据已测量的BaF₂探测器时间分辨率（159 ps），可计算得到所设计的TOF-PET探测器时间分辨率为344 ps。预计与此相同的两个TOF-PET探测器对正电子湮没射线的符合时间分辨率可达486 ps左右，为新型PET的研究提供了有利条件。

Abstract: In this work, LYSO scintillators and position sensitive photomultiplier tube (PS-PMT) were used to design the TOF-PET detector, and LYSO crystals of 3.2 mm×3.2 mm pitch could be distinguished. The coincidence time resolution of 379 ps was measured for the γ rays produced by positron annihilation with a reference detector of BaF₂, whose time resolution for 511 keV γ ray was measured as 159 ps. By subtracting the contribution of the BaF₂ detector, 344 ps time resolution could be calculated for the designed TOF-PET detector, and 486 ps coincidence time resolution for γ rays of positron annihilation can be expected for two such detectors. It means that the new detector for TOF-PET is feasible.