Dual APD array readout of LSO crystals: Optimization of crystal surface treatment
Dual APD array readout of LSO crystals: Optimization of crystal surface treatment
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DOI：
10.1109/tns.2002.1039544
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发表时间：
2002-06-01
影响因子：
1.8
通讯作者：
Cherry, SR
中科院分区：
文献类型：
--
作者：
Shao, Y;Meadors, K;Cherry, SR
我们正在开发一种紧凑的正电子发射断层扫描（PET）探测器模块，该模块基于氧化硅酸镥（LSO）闪烁体阵列，两端通过雪崩光电二极管（APD）阵列耦合，具有相互作用深度（DOI）。这导致检测器具有高灵敏度，可以提供高和均匀的图像分辨率。我们报道了通过优化晶体表面处理来提高DOI分辨率的研究。6个2 x 2 x 20 mm的LSO晶体沿其长度进行了不同的表面处理：原始锯切，抛光光学表面处理，以及用热无水磷酸（h - 3po4）化学蚀刻，蚀刻时间从1到5分钟不等。用两个APD阵列发出的信号之比来测量DOI，用信号之和来测量总光输出。化学蚀刻2-3分钟完成的晶体提供了最佳的探测器整体性能，对于高于150 kev阈值的事件，DOI分辨率在3.1到3.9 min之间，不同DOI位置的光输出均匀。能量分辨率在14%到18%之间。这种检测器设计在PET应用中具有很高的分辨率和灵敏度，例如小动物成像和人类乳房成像。
We are developing a compact positron emission tomography (PET) detector module with a depth of interaction capability (DOI) based on a lutetium oxyorthosilicate (LSO) scintillator array coupled at both ends by avalanche photodiode (APD) arrays. This leads to a detector with high sensitivity that can provide high and uniform image resolution. We report studies on improving the DOI resolution by optimizing the crystal surface treatment. Six 2 x 2 x 20 mm LSO crystals were treated with different surface finishes along their length: raw saw-cut, polished optical finish, and chemically etched by hot anhydrous phosphoric acid (H-3 PO4) with etching times varying from 1 to 5 min. The ratio of the signals from the two APD arrays was used to measure DOI, and the sum of the signals to measure the total light output. Crystals finished by chemical etching for 2-3 min gave the best overall detector performance, with DOI resolutions ranging from 3.1 to 3.9 min for events above a 150-keV threshold and uniform light output for different DOI positions. The energy resolution ranged between 14% and 18%. This detector design appears promising for PET applications requiring very high resolution and high sensitivity, for example, in small animal imaging and human breast imaging.