Evaluation and optimization of geometry parameters of GAGG scintillator-based Compton Camera for medical imaging by Monte Carlo simulation
Evaluation and optimization of geometry parameters of GAGG scintillator-based Compton Camera for medical imaging by Monte Carlo simulation
复制标题
通过蒙特卡罗模拟评估和优化用于医学成像的基于 GAGG 闪烁体的康普顿相机的几何参数
DOI：
10.1088/1748-0221/18/01/p01035
复制
发表时间：
2023
影响因子：
1.3
通讯作者：
Watabe H.
中科院分区：
文献类型：
--
作者：
Zarei H.;Razaghi S.;Nagao Y.;Itoh M.;Yamaguchi M.;Kawachi N.;Ay M.R.;Watabe H.
在核医学中，开发具有高成像分辨率和灵敏度、能够对具有宽能量范围和多种放射性同位素示踪能力的伽马射线进行成像的便携式成像设备非常重要。这些目标已经成为可能，由于开发了一个紧凑的康普顿相机，准直器耦合到紧凑的硅光电倍增管（SiPM）阵列检测器，使用闪烁晶体。在这项研究中，便携式分段GAGG：Ce闪烁器为基础的康普顿相机（CC）进行了优化与GATE，基于Geant 4的蒙特卡罗模拟工具包，以最大限度地提高其性能的伽马射线能量范围广泛（364-1000千电子伏）。选取几何参数作为优化参数，研究了几何参数对成像分辨率和绝对探测效率（DEa）的影响。CC的几何参数包括散射体和吸收体探测器的平面面积、它们的厚度以及它们之间的距离。在364-1000 keV的能量范围内的结果表明，对相机的空间分辨率和DE a最重要的贡献是SAD（散射体到吸收体的距离）和散射体面积，而改变吸收体面积（AA）显示出最可忽略的影响。在短SAD中，成像分辨率和DE a受探测器的尺寸和厚度的显著影响。另一方面，在长SAD（> 4cm）中，空间分辨率和DEa均受探测器面积的显著影响，而受探测器厚度的影响较小。减小散射体的厚度和吸收体的尺寸或厚度提高了成像分辨率，而没有显著减小DE a。模拟研究的结果将提供有价值的指导研究人员选择一个所需的CC的设计，根据特定的目标，在闪烁体生长，成本等的制造限制。
In nuclear medicine, the development of portable imaging devices that provide high imaging resolution and sensitivity, capable of imaging gamma rays with a wide energy range and multiple radioisotopes tracing capabilities, is so important. These goals have been possible thanks to developing a compact Compton camera, a collimatorless detector coupled to compact silicon photomultiplier (SiPM) array, using scintillator crystal. In this study, the portable segmented GAGG: Ce scintillator-based Compton camera (CC) is optimized with the GATE, a Monte Carlo simulation toolkit based on Geant4, to maximize its performance for a wide range of gamma-ray energy (364–1000 keV). The geometrical parameters are selected as optimization parameters to investigate their effects on CC's performance, including imaging resolution and absolute detection efficiency (DE a). The geometry parameters of CC include the planner area of scatterer and absorber detectors, their thicknesses, and the distance between them. The results for the energy range of 364–1000 keV show that the most important contributions to the spatial resolution and DE a of the camera are SAD (scatterer to absorber distance) and the scatterer area while changing absorber area (A A) showed the most negligible impact. In the short SADs, imaging resolution and DE a are significantly affected by the detector's size and thickness. On the other hand, in the long SADs (> 4 cm), both spatial resolution and DE a are significantly affected by the detector's area but less affected by the detector's thickness. Decreasing the scatterer's thickness and the absorber's size or thickness improves imaging resolution without significantly reducing DE a. The simulation study's findings presented here will provide valuable guidelines for researchers choosing a desired CC's design according to particular objectives, manufacturing limitations in scintillator growth, cost, etc.