Scintillation crystal design features for a miniature gamma ray camera
Scintillation crystal design features for a miniature gamma ray camera
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DOI：
10.1109/tns.2005.858178
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发表时间：
2005-10-01
影响因子：
1.8
通讯作者：
Habte, F
中科院分区：
文献类型：
--
作者：
Dhanasopon, AP;Levin, CS;Habte, F
一种具有5厘米x 5厘米视野(FOV)的微型闪烁相机正在开发中，以帮助癌症的外科分期。本文报道了闪烁晶体阵列的一些有趣的设计方面。对不同类型的晶体材料的模拟和测量表明，PET中常用的氧硅酸锂(LSO)材料具有探测140keV光子的良好性能。例如，在140keV时，LSO只需要3朗姆的厚度就可以获得95%的探测效率。这种较小的厚度要求高的光收集效率、窄的光分布和最小化的LSO体积，以便减少Lu-176(2.6%丰度)产生的本征背景事件。对离散晶体和片状晶体的研究表明，与片状晶体相比，离散晶体阵列具有更高的空间线性度和动态范围。为了优化灵敏度和空间分辨率，研究了几种晶体阵列条件，包括地面晶体像素与内部反射器紧密堆积在一起，以及使用光学耦合润滑脂。这种设计聚焦了光线，但也允许与将用于伽马相机的位置敏感光电倍增管(PSPMX)进行足够的光共享以进行定位。
A miniature scintillation camera with a 5 cm x 5 cm field-of-view (FOV) is being developed to aid in surgical staging of cancer. This paper reports on certain interesting design aspects of the scintillation crystal array. Simulations and measurements of different types of crystal materials revealed that lutetium oxyorthosilicate (LSO), which is ordinarily used in PET, has appealing properties for detecting 140 keV photons. For example, LSO requires only 3 rum of thickness for 95% detection efficiency at 140 keV. This small thickness is appealing for high light collection efficiency, narrow light distribution, and minimizing the LSO volume in order to reduce intrinsic background events produced by Lu-176 (2.6% abundance). Studies of both discrete and sheet crystals revealed that discrete crystal arrays have the advantage of increased spatial linearity and dynamic range compared to crystal sheets. For optimizing sensitivity and spatial resolution, several crystal array conditions were investigated, including ground crystal pixels packed tightly together with internal reflectors and with optical coupling grease. This design focuses the light, but also allows adequate light sharing for positioning with the position sensitive photomultiplier tube (PSPMX) that will be used in the gamma camera.