Development of a high-resolution Si-PM-based gamma camera system
Development of a high-resolution Si-PM-based gamma camera system
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DOI：
10.1088/0031-9155/56/23/014
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发表时间：
2011-12
影响因子：
3.5
通讯作者：
S. Yamamoto;H. Watabe;Y. Kanai;M. Imaizumi;T. Watabe;E. Shimosegawa;J. Hatazawa
中科院分区：
文献类型：
--
作者：
S. Yamamoto;H. Watabe;Y. Kanai;M. Imaizumi;T. Watabe;E. Shimosegawa;J. Hatazawa
硅光电倍增管（Si-PM）具有增益高、体积小、对静磁场灵敏度低等优点，是一种很有前途的PET光电探测器，尤其适用于PET/MRI联合系统。然而，这些属性也是有前途的单光子成像的伽马相机系统。我们开发了一种用于小动物的超高分辨率Si-PM紧凑型伽马相机系统。选择Y_2SiO_5：Ce（YSO）作为发光材料是因为它具有高的光输出和无天然放射性。伽马相机由0.6 mm × 0.6 mm × 6 mm YSO像素和0.1 mm厚反射器组成，形成17 × 17矩阵，该矩阵与具有2 mm厚光导的Si-PM阵列（Hamamatsu多像素光子计数器S11064- 050 P）光耦合。YSO块的尺寸为12 mm × 12 mm。YSO伽马相机装入5 mm厚的伽马屏蔽罩中，平行孔准直器安装在相机前面（0.5 mm孔，0.7 mm间距，5 mm厚）。Co-57 γ光子（122 keV）的二维分布几乎得到解决。对于Co-57伽马光子，能量分辨率为24.4%半高全宽（FWHM）。在距离准直器表面1.5 mm处的空间分辨率为1.25 mm FWHM，使用1 mm直径的Co-57点源测量。成功获得体模和小动物图像。我们的结论是，一个硅PM为基础的伽马相机是有前途的分子成像研究。
A silicon photomultiplier (Si-PM) is a promising photodetector for PET, especially for PET/MRI combined systems, due to its high gain, small size, and lower sensitivity to static magnetic fields. However, these properties are also promising for gamma camera systems for single-photon imaging. We developed an ultra-high-resolution Si-PM-based compact gamma camera system for small animals. Y2SiO5:Ce (YSO) was selected as scintillators because of its high light output and no natural radioactivity. The gamma camera consists of 0.6 mm × 0.6 mm × 6 mm YSO pixels combined with a 0.1 mm thick reflector to form a 17 × 17 matrix that was optically coupled to a Si-PM array (Hamamatsu multi-pixel photon counter S11064-050P) with a 2 mm thick light guide. The YSO block size was 12 mm × 12 mm. The YSO gamma camera was encased in a 5 mm thick gamma shield, and a parallel hole collimator was mounted in front of the camera (0.5 mm hole, 0.7 mm separation, 5 mm thick). The two-dimensional distribution for the Co-57 gamma photons (122 keV) was almost resolved. The energy resolution was 24.4% full-width at half-maximum (FWHM) for the Co-57 gamma photons. The spatial resolution at 1.5 mm from the collimator surface was 1.25 mm FWHM measured using a 1 mm diameter Co-57 point source. Phantom and small animal images were successfully obtained. We conclude that a Si-PM-based gamma camera is promising for molecular imaging research.