3-D Spatial Resolution of 350 μm Pitch Pixelated CdZnTe Detectors for Imaging Applications.
3-D Spatial Resolution of 350 μm Pitch Pixelated CdZnTe Detectors for Imaging Applications.
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用于成像应用的 600 μm 节距像素化 CZT 探测器的电荷共享效应
DOI：
10.1109/tns.2012.2213611
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发表时间：
2013-02
影响因子：
1.8
通讯作者：
Tai YC
中科院分区：
文献类型：
--
作者：
Yin Y;Chen X;Wu H;Komarov S;Garson A 3rd;Li Q;Guo Q;Krawczynski H;Meng LJ;Tai YC
我们目前正在研究使用高度像素化的碲锌镉（CdZnTe）探测器用于亚500 μm分辨率PET成像应用的可行性。制作了20 mm × 20 mm × 5 mm的CdZnTe衬底，像素间距为350 μm（250 μm阳极像素，100 μm间隙），共面阴极。利用准直的122 keV和511 keV γ射线源研究了350 μm间距探测器像素间的电荷共享。对于间距为350 μm的CdZnTe探测器，当准直光束入射到相邻像素之间的差距时，两个相邻像素的电荷信号的散点图清楚地显示出更多的电荷共享。使用准直的Co-57和Ge-68源，我们测量了计数分布，并估计了偏置在-1000 V的350 μm间距探测器的固有空间分辨率。基于两种方法分析了相互作用的深度，即，阴极/阳极比和电子漂移时间，在122 keV和511 keV的测量。对于单像素峰值事件，阴极/阳极比和电子漂移时间之间的线性相关性被示出，这将是有用的估计DOI信息和保持图像分辨率在CdZnTe PET成像应用。
We are currently investigating the feasibility of using highly pixelated Cadmium Zinc Telluride (CdZnTe) detectors for sub-500 μm resolution PET imaging applications. A 20 mm × 20 mm × 5 mm CdZnTe substrate was fabricated with 350 μm pitch pixels (250 μm anode pixels with 100 μm gap) and coplanar cathode. Charge sharing among the pixels of a 350 μm pitch detector was studied using collimated 122 keV and 511 keV gamma ray sources. For a 350 μm pitch CdZnTe detector, scatter plots of the charge signal of two neighboring pixels clearly show more charge sharing when the collimated beam hits the gap between adjacent pixels. Using collimated Co-57 and Ge-68 sources, we measured the count profiles and estimated the intrinsic spatial resolution of 350 μm pitch detector biased at −1000 V. Depth of interaction was analyzed based on two methods, i.e., cathode/anode ratio and electron drift time, in both 122 keV and 511 keV measurements. For single-pixel photopeak events, a linear correlation between cathode/anode ratio and electron drift time was shown, which would be useful for estimating the DOI information and preserving image resolution in CdZnTe PET imaging applications.