基于三维正交条形碲锌镉探测器的DOI-PET显像研究

为对511 keV伽马光子进行三维定位，提高PET显像性能，研制一种尺寸为16.4 mm×16.4 mm×5 mm正交条形碲锌镉（CZT）探测器，并测试其PET显像性能。在32个电极读出后均采用电荷灵敏前置放大器和滤波放大模块，输入高速模数转换器对数据进行采样，得到探测器中信号的全脉冲形状，并利用模拟数字转换器（ADC）内置可编程门列阵（FPGA）对信号进行在线处理，对信号完成寻峰、滤波等数字化处理。结果表明，该碲锌镉探测器对511 keV伽玛光子的能量分辨率为6.35%，通过对碲锌镉探测器的电极结构分析得出了一套伽马光子相互作用的三维位置坐标计算公式，可以达到亚毫米位置分辨率，实现了碲锌镉探测器三维显像功能。

DOI-PET Imaging Investigation Based on 3-D Cross-Strip Cadmium Zinc Telluride Detector

To study the PET imaging performance of cross-strip cadmium zinc telluride detector with a size of 16.4 mm×16.4 mm×5 mm, which can determine the 3-D position information of 511 keV gamma photons. The 32 electrodes of the detector are all read out using charge sensitive preamplifiers and filter amplification modules, and then input high-speed analog-to-digital converters to sample the data, and obtain the full pulse shape of the signal in the detector, and use the ADC built-in FPGA to perform the online signal processing, digital processing such as peak finding and filtering. The energy resolution of the CZT detector for 511 keV gamma photons is 6.35%. According to the electrode structure of the CZT detector, 3-D position coordinate calculation formulas for the interaction of gamma photons can be obtained. The CZT detector realizes a 3-D imaging function with a sub-millimeter resolution.