X’tal Cube PET Detector Composed of a Stack of Scintillator Plates Segmented by Laser Processing
X’tal Cube PET Detector Composed of a Stack of Scintillator Plates Segmented by Laser Processing
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X’tal Cube PET 探测器由一堆激光加工分段的闪烁体板组成
DOI：
10.1109/tns.2013.2293599
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发表时间：
2014
影响因子：
1.8
通讯作者：
and Taiga Yamaya
中科院分区：
文献类型：
--
作者：
Naoko Inadama;Takahiro Moriya;Yoshiyuki Hirano;Fumihiko Nishikido;Hideo Murayama;Eiji Yoshida, Hideaki Tashima;Munetaka Nitta;Hiroshi Ito;and Taiga Yamaya
我们研制了一种可应用于PET探测器的三维位置敏感辐射探测器X 'tal cube。X 'tal立方体由闪烁晶体块和多像素光子计数器（MPPC）组成。晶体块通过光学不连续性（3-D分割）被三维分割成小立方体，并且内部没有插入反射器。闪烁光起源于一个片段，然后扩散三维，使MPPC设置在所有六个表面的晶体块，以检测光。关于晶体块的3-D分割，我们已经成功地通过激光加工技术而不是一般的方式，将小立方体闪烁体元件排列成3-D阵列，来获得单片闪烁体块内部的分割。我们已经证实，利用激光加工技术不仅消除了处理小闪烁体元件的困难，而且提高了探测器的性能。作为一种新的尝试，我们考虑通过堆叠闪烁体板来制造晶体块，所述闪烁体板通过激光加工技术（2-D分割）被二维分割。板也更容易处理，对于激光加工，2-D分割比3-D分割更简单。在这项研究中，我们准备了X 'tal立方体与闪烁体板（Plate-XC），并评估其性能，以确认其技术的可行性。对于Plate-XC，我们通过激光加工对18 mm × 18 mm × 2.0 mm LYSO板进行二维分割，以制作2.0 mm × 2.0 mm片段的9 × 9阵列。晶体块由9个堆叠的LYSO板组成，不使用耦合材料，但具有气隙。Plate-XC在662 keV γ射线照射下显示出足够的晶体识别性能。此外，为了了解Plate-XC的特性，我们还分析了晶体块中的闪烁光分布。结果表明，从外部段的光传播的影响，段的边界条件，空气间隙或激光处理的间隙，而从中心段的传播似乎没有这样的影响。关于能量性能，我们获得了大约10%的能量分辨率的外部段以及中心段。
We have developed a three-dimensional (3-D) position-sensitive radiation detector named X'tal cube, which can be applied to a PET detector. The X'tal cube is composed of a scintillation crystal block and multi-pixel photon counters (MPPCs). The crystal block is segmented three-dimensionally into small cubes by optical discontinuity (3-D segmentation) and no reflector is inserted inside. Scintillation light originating in a segment then spreads three-dimensionally so that the MPPCs are set on all six surfaces of the crystal block to detect the light. Regarding the 3-D segmentation of the crystal block, we have already succeeded in getting the segmentation inside of a monolithic scintillator block by a laser processing technique instead of the general way, arranging small cubic scintillator elements into a 3-D array. We have confirmed that utilizing the laser processing technique not only eliminates the difficulty of handling the small scintillator elements but also improves detector performance. As a new trial, we considered fabrication of the crystal block by stacking the scintillator plates which were segmented two-dimensionally by the laser processing technique (2-D segmentation). Plates are also easier to handle and for the laser processing, 2-D segmentation is simpler than 3-D segmentation. In this study, we prepared the X'tal cube with the scintillator plates (Plate-XC) and evaluated its performance to confirm its technical feasibility. For the Plate-XC, we segmented 18 mm × 18 mm × 2.0 mm LYSO plates two-dimensionally by laser processing so as to make a 9 × 9 array of 2.0 mm × 2.0 mm segments. The crystal block was composed of 9 stacked LYSO plates without using coupling material but with air gaps. The Plate-XC showed sufficient crystal identification performance when 662 keV gamma-rays were irradiated. Furthermore, to understand the characteristics of the Plate-XC, we also analyzed the scintillation light distribution in the crystal block. Results indicated that light spread from outer segments was influenced by the segment boundary conditions, air gaps or laser-processed gaps, while the spread from the center segment did not seem to have such an influence. Regarding energy performance, we obtained around 10% energy resolution for the outer segments as well as for the center segment.