A rectangular-shaped PET system with an adjustable gantry (AGPET) has been developed for imaging small animals. The AGPET system employs a new depth of interaction (DOI) method using a depth dependent reflector patterns and a new digital time pickoff method based on the pulse reconstruction method. To evaluate the performance of the AGPET, timing resolution, intrinsic spatial resolution and point source images were acquired. The timing resolution and intrinsic spatial resolution were measured using two detector modules and Na-22 gamma source. The PET images were acquired in two field of view (FOV) sizes, 30 mm and 90 mm, to demonstrate the characteristic of the AGPET. As a result of in the experiment results, the timing resolution was 0.9 ns using the pulse reconstruction method based on the bi-exponential model. The intrinsic spatial resolution was an average of 1.7 mm and the spatial resolution of PET images after DOI correction was 2.08 mm and 2.25 mm at the centers of 30 mm and 90 mm FOV, respectively. The results show that the proposed AGPET system provided higher sensitivity and resolution for small animal imaging.

已开发出带有可调节机架 (AGPET) 的矩形 PET 系统，用于对小动物进行成像。AGPET 系统采用一种新的交互深度 (DOI) 方法，该方法使用依赖于深度的反射器模式和一种基于脉冲重建方法的新数字时间拾取方法。为了评估 AGPET 的性能，获取了时间分辨率、固有空间分辨率和点源图像。使用两个探测器模块和 Na-22 伽马源测量时间分辨率和固有空间分辨率。PET 图像以两种视场 (FOV) 尺寸（30 毫米和 90 毫米）获取，以展示 AGPET 的特性。实验结果表明，基于双指数模型的脉冲重构方法的时序分辨率为0.9 ns。内在空间分辨率平均为 1.7 mm，DOI 校正后 PET 图像在 30 mm 和 90 mm FOV 中心的空间分辨率分别为 2.08 mm 和 2.25 mm。结果表明，所提出的 AGPET 系统为小动物成像提供了更高的灵敏度和分辨率。