PSPMT/APD hybrid DOI detectors for the PET component of a dedicated breast PET/CT system - A feasibility study
PSPMT/APD hybrid DOI detectors for the PET component of a dedicated breast PET/CT system - A feasibility study
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DOI：
10.1109/tns.2008.924073
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发表时间：
2008-06-01
影响因子：
1.8
通讯作者：
Badawi, Ramsey D.
中科院分区：
文献类型：
--
作者：
Chaudhari, Abhijit J.;Yang, Yongfeng;Badawi, Ramsey D.
我们探索了两种具有高有效填充分数的相互作用深度（DOI）检测器，用于下一代圆柱形悬挂式乳腺PET/CT扫描仪的PET部分。所提出的双读出探测器包括一个未抛光的（14 x 14）阵列（1.5 x 1.5 x 20）mm（3）LSO晶体耦合到位置敏感PMT（PSPMT）在后端的位置感测和（A）（2 x 2）矩阵雪崩光电二极管（APD）或（B）一个单一的大APD在前端测量DOI。通过选择APD使得APD矩阵或单个大APD的总前表面接触面积与晶体阵列的接触面积和PSPMT的有源面积两者近似匹配来实现增加的有效填充分数。这导致当放置在圆柱形扫描器几何形状中时相邻检测器之间的死空间减小。我们建议通过使用相邻晶体的光学串扰来恢复由于APD的非活性区域而部分被遮挡的晶体的DOI。我们利用五个原型模块进行了初步研究：其中两个使用（1.5 x 1.5 x 20）mm（3）LSO晶体的（9 x 9）阵列，三个使用（1.5 x 1.5 x 30）mm 3晶体的（14 x 14）LSO阵列。通过前端的（8 x 8）mm（2）、（14 x 14）mm（2）或（28 x 28）mm（2）位置敏感APD（PSAPD）和后端的PSPMT进行读出。在室温下，平均能量和DOI分辨率仅下降了
We explore two depth of interaction (DOI) capable detectors with a high effective packing fraction to be used for the PET portion of a next generation cylindrical pendant breast PET/CT scanner. The proposed dual-readout detectors consist of an unpolished (14 x 14) array of (1.5 x 1.5 x 20) mm(3) LSO crystals coupled to a position sensitive-PMT (PSPMT) at the back end for position sensing and either (A) a (2 x 2) matrix of avalanche photodiodes (APDs) or (B) a single large APD at the front end for measuring DOI. Increased effective packing fraction is achieved by choosing the APDs such that the total front surface contact area of the APD matrix or the single large APD approximately matches both the contact area of the crystal array and the active area of the PSPMT. This results in reduced dead space between adjacent detectors when placed in a cylindrical scanner geometry. We propose to recover DOI for the crystals that are partially occluded due to the inactive area of the APD by using the optical crosstalk from neighboring crystals. We conducted preliminary studies utilizing five prototype modules: two of which used a (9 x 9) array of (1.5 x 1.5 x 20) mm(3) LSO crystals, and three that used a (14 x 14) LSO array of (1.5 x 1.5 x 30) mm 3 crystals. The readout was performed either by a (8 x 8) mm(2), (14 x 14) mm(2) or a (28 x 28) mm(2) position sensitive-APD (PSAPD) at the front end and a PSPMT at the rear end. At room temperature, the average energy and DOI resolutions degraded only by