Department of Radiation Science and Technology, Delft University of Technology, the Netherlands.
Appl Radiat Isot. 2021 Feb;168:109368. doi: 10.1016/j.apradiso.2020.109368. Epub 2020 Oct 24.
Over the last decade one of the most significant technological advances made in the field of radiation detectors for nuclear medicine was the development of Silicon Photomultipler (SiPM) sensors. At present only a small number of SiPM based radiation detectors for Single Photon Emission Computed Tomography (SPECT) applications have been explored, and even fewer experimental prototypes developed. An in-silico investigation into the optimal design of a Philips DPC3200 SiPM photosensor-based thin monolithic scintillator detector for SPECT applications was undertaken using the Monte Carlo radiation transport modelling toolkit Geant4 version 10.5. The performance of the 20 different SPECT radiation detector configurations, 4 scintillator materials (NaI(Tl), GAGG(Ce), CsI(Tl) and LaBr(Ce)) and 5 thicknesses (1-5 mm), were determined through the use of seven figures of merit. It was found that a crystal thickness range of 4-5 mm was required for all four materials to ensure acceptable energy resolution, sensitivity and spatial resolution performance with the Philips DPC3200 SiPM. Any thinner than this and the performance of all four materials was found to degrade rapidly due to a high probability of material specific fluorescence x-ray escape after incident gamma/x-ray photoelectric absorption. When factoring in each material's magnetic resonance imaging compatibility, hygroscopy, and cost, it was found that CsI(Tl) represents the most promising material to construct tileable Philips digital SiPM based thin monolithic scintillator detectors for SPECT applications.
在过去的十年中，核医学辐射探测器领域取得的最重要技术进步之一是硅光电倍增管（SiPM）传感器的发展。目前，只有少数基于 SiPM 的单光子发射计算机断层扫描（SPECT）应用辐射探测器得到了探索，开发的实验原型更少。使用蒙特卡罗辐射传输建模工具包 Geant4 版本 10.5 对飞利浦 DPC3200 SiPM 光电传感器为基础的用于 SPECT 应用的薄型单片闪烁体探测器的最佳设计进行了计算机模拟研究。通过使用七个性能指标，确定了 20 种不同的 SPECT 辐射探测器配置、4 种闪烁体材料（NaI(Tl)、GAGG(Ce)、CsI(Tl)和 LaBr(Ce)）和 5 种厚度（1-5mm）的性能。结果发现，对于所有四种材料，都需要 4-5mm 的晶体厚度范围，以确保在飞利浦 DPC3200 SiPM 下具有可接受的能量分辨率、灵敏度和空间分辨率性能。任何比这更薄的材料，所有四种材料的性能都会迅速下降，因为在入射伽马/ X 射线光电吸收后，荧光 X 射线逃逸的可能性很高。在考虑每种材料的磁共振成像兼容性、吸湿性和成本后，发现 CsI(Tl) 是最有前途的材料，可以构建用于 SPECT 应用的可平铺的飞利浦数字 SiPM 基于薄型单片闪烁体探测器。
