The crosshair light-sharing (CLS) PET detector is our original depth-of-interaction (DOI) detector, which is based on a single-ended readout scheme with quadrisected crystals comparable in size to a photo-sensor. In this work, we developed 32 CLS PET detectors, each of which consisted of a multi-pixel photon counter (MPPC) array and gadolinium fine aluminum garnet (GFAG) crystals, and we developed a benchtop prototype of a small animal size PET. Each GFAG crystal was 1.45נ1.45נ15 mm³. The MPPC had a surface area of 3.0נ3.0 mm². The benchtop prototype had two detector rings of 16 detector blocks. The ring diameter and axial field-of-view were 14.2 cm and 4.9 cm, respectively. The data acquisition system used was the PETsys silicon photomultiplier readout system. The continuous DOI information was binned into three DOI layers by applying a look-up-table to a 2D position histogram. Also, energy and timing information was corrected using DOI information. After the calibration procedure, the energy resolution and the coincidence time resolution were 14.6% and 531 ps, respectively. Imaging test results of a small rod phantom obtained by an iterative reconstruction method showed clear separation of 1.6 mm rods with the help of DOI information.

十字准线光共享 (CLS) PET 检测器是我们最初的交互深度 (DOI) 检测器，它基于单端读出方案，四等分晶体的尺寸与光传感器相当。在这项工作中，我们开发了 32 个 CLS PET 探测器，每个探测器由一个多像素光子计数器 (MPPC) 阵列和钆细铝石榴石 (GFAG) 晶体组成，我们开发了一个小型动物大小 PET 的台式原型。每个 GFAG 晶体为 1.45נ1.45נ15 mm ³。MPPC 的表面积为 3.0נ3.0 mm ². 台式原型有两个由 16 个探测器块组成的探测器环。环直径和轴向视野分别为 14.2 厘米和 4.9 厘米。使用的数据采集系统是 PETsys 硅光电倍增管读出系统。通过将查找表应用于 2D 位置直方图，将连续 DOI 信息分箱为三个 DOI 层。此外，使用 DOI 信息更正了能量和时间信息。校准程序后，能量分辨率和符合时间分辨率分别为 14.6% 和 531 ps。通过迭代重建方法获得的小棒体模的成像测试结果显示，在 DOI 信息的帮助下，1.6 mm 的棒清晰分离。