SemiSPECT: A small-animal single-photon emission computed tomography (SPECT) imager based on eight cadmium zinc telluride (CZT) detector arrays
SemiSPECT: A small-animal single-photon emission computed tomography (SPECT) imager based on eight cadmium zinc telluride (CZT) detector arrays
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DOI：
10.1118/1.2164070
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发表时间：
2006-02-01
期刊：
影响因子：
3.8
通讯作者：
Barrett, HH
中科院分区：
文献类型：
--
作者：
Kim, H;Furenlid, LR;Barrett, HH
第一台全单光子发射计算机断层成像(SPECT)成像仪，开发了八种紧凑型高本征分辨率碲化镉锌镉(CZT)探测器，称为SemiSPECT。已经完成了。每个探测器由CZT晶体和定制的专用集成电路(ASIC)组成。CZT晶体为2.7cmx2.7cmx，类似于0.2 cm板条，具有连续的上电极和下电极，并通过光刻形成X像素阵列。ASIC通过铟-凸点键合的方式连接到CZT晶体的底部。在连续电极上施加-180V的偏压。这八个探测器排列在一个八角形的铅屏蔽环中。放置在环中心的八个针孔中的每个针孔与每个单独的探测器阵列相匹配。通过针孔将物体成像到每个探测器上，每个探测器以列表模式采集独立操作。成像对象可以绕垂直轴旋转以获得额外的角度投影。用~(99m)Tc对半断层显像性能进行了表征。当使用0.5 mm直径的针孔时，根据傅里叶串扰矩阵估计，每个轴上的空间分辨率约为1.4 mm，该矩阵提供了视场上与算法无关的平均分辨率。通过在3x3窗口中对相邻像素信号求和而获得的能量分辨率大约是光峰值的10%全宽。整个系统的灵敏度约为0.5x10(-4)，能量窗距离光峰为10%。线模图像被用来可视化SemiSPECT所提供的空间分辨率，并且小鼠骨、心肌和人类肿瘤异种移植的图像证明了SemiSPECT用于临床前小动物研究的可行性。(C)2006年美国医学物理学家协会。
The first full single-photon emission computed tomography (SPECT) imager to exploit eight compact high-intrinsic-resolution cadmium zinc telluride (CZT) detectors, called SemiSPECT. has been completed. Each detector consists of a CZT crystal and a customized application-specific integrated circuit (ASIC). The CZT crystal is a 2.7 cm x 2.7 cm x similar to 0.2 cm slab with a continuous top electrode and a bottom electrode patterned into a 64 X 64 pixel array by photolithography. The ASIC is attached to the bottom of the CZT crystal by indium-bump bonding. A bias voltage of -180 V is applied to the continuous electrode. The eight detectors are arranged in an octagonal lead-shielded ring. Each pinhole in the eight-pinhole aperture placed at the center of the ring is matched to each individual detector array. An object is imaged onto each detector through a pinhole, and each detector is operated independently with list-mode acquisition. The imaging subject can be rotated about a vertical axis to obtain additional angular projections. The performance of SemiSPECT was characterized using Tc-99m. When a 0.5 mm diameter pinhole is used, the spatial resolution on each axis is about 1.4 mm as estimated by the Fourier crosstalk matrix, which provides an algorithm-independent average resolution over the field of view. The energy resolution achieved by summing neighboring pixel signals in a 3x3 window is about 10% full-width-at-half-maximum of the photopeak. The overall system sensitivity is about 0.5x10(-4) with the energy window of 10% from the photopeak. Line-phantom images are presented to visualize the spatial resolution provided by SemiSPECT, and images of bone, myocardium, and human tumor xenografts ill mice demonstrate the feasibility of preclinical small-animal studies with SemiSPECT. (c) 2006 American Association of Physicists in Medicine.