A dual layer DOI GSO block detector for a small animal PET
A dual layer DOI GSO block detector for a small animal PET
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DOI：
10.1016/j.nima.2008.09.014
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发表时间：
2009-01
影响因子：
1.4
通讯作者：
S. Yamamoto
中科院分区：
文献类型：
--
作者：
S. Yamamoto
对于高分辨率的动物正电子发射断层扫描(PET)，相互作用深度(DOI)是提高空间分辨率和灵敏度的有效方法。不同Ce掺杂量的Gd2SiO5(GSO)可以提供不同的衰减时间，是脉冲波形分析DOI探测器的理想材料。针对一种新型的动物PET，研制了不同Ce掺杂量的双层DOI GSO阻挡探测器。DOI GSO阻挡探测器使用了两种类型的GSO：一种是Ce浓度为1.5mol%的GSO(衰变时间为35 ns)，另一种是Ce浓度为0.5mol%的GSO(衰变时间为60 ns)。这两种类型的GSO在DOI方向上是光学耦合的。当摩尔分数为1.5和0.5时，单个GSO的尺寸分别为1.9 mm×1.9 mm×6 mm和1.9 mm×1.9 mm×9 mm。这些GSO由11×37矩阵排列，并与三个位置灵敏光电倍增管(PSPMT)光学耦合，其中PSPMT使用的PSPMT是滨松R8520U-00-C12。在晶体之间采用不同长度的反射镜，以增加PSPMT的有效视场，避免PSPMT之间的死区。利用这种配置，对应于GSO单元的2D位置直方图中的几乎所有岛都可以被分离。GSO块横径为22 mm，横径为74 mm，无间隙。此外，利用脉冲波形分析的对偶积分方法可以分离出两种不同衰变时间的GSO。这些结果表明，所开发的块状探测器可能用于具有双层DOI检测能力的高分辨率和高灵敏度的动物PET，在横轴或轴向上没有间隙。
For a high resolution animal positron emission tomography (PET), depth-of-interaction (DOI) is a useful method to improve both spatial resolution and sensitivity. Gd2SiO5(GSO) with different amounts of Ce can provide different decay times and is ideal for DOI detector using pulse shape analysis. Dual layer DOI GSO block detectors using different amounts of Ce were developed for a new animal PET. The DOI GSO block detector employed two types of GSOs; one with 1.5mol% Ce concentration (decay time: 35ns) and the other with 0.5mol% (decay time: 60ns). These two GSO types were optically coupled in the DOI direction. The sizes of single GSOs were 1.9mm×1.9mm×6mm and 1.9mm×1.9mm×9mm, for 1.5 and 0.5mol%, respectively. These GSO were arranged by 11×37 matrix and optically coupled to three position sensitive photomultiplier tubes (PSPMTs), where the PSPMTs used were Hamamatsu R8520U-00-C12. Different lengths of reflectors were used between crystals to increase the useful field-of-view (FOV) of the PSPMT and to avoid the dead areas between PSPMTs. With this configuration, almost all islands in a 2-D position histogram corresponding to GSO cells could be separated. The width of the GSO block was 22mm in the transaxial direction and 74mm in axial direction with no gaps. Also, two types of GSO of different decay time could be separated using dual integration method for pulse shape analysis. These results indicate that developed block detectors might be useful for a high resolution and high sensitivity animal PET with dual layer DOI detection capability, with no gaps in transaxial or axial directions.