An electronically collimated gamma camera for single photon emission computed tomography. Part I: Theoretical considerations and design criteria.
An electronically collimated gamma camera for single photon emission computed tomography. Part I: Theoretical considerations and design criteria.
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DOI：
10.1097/00004728-198312000-00071
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发表时间：
1983-12
期刊：
影响因子：
3.8
通讯作者：
M. Singh
中科院分区：
文献类型：
--
作者：
M. Singh
研究了一种用于单光子发射计算机层析成像的新型伽马相机的探测和成像特性。与使用机械准直的传统伽马相机不同，新的伽马相机使用电子准直，这是通过伽马辐射与双重位置和能量敏感检测系统的顺序相互作用获得的。两个探测器之间的重合计数提供了在整个物体的多个圆锥面上的活度定位，由此可以重建三维活度分布。电子准直不仅提供了物体的同时多个视角，而且在类似空间分辨率的条件下，与传统的准直伽马相机相比，灵敏度也有很大的提高。进行了探测器优化研究，以设计一个原型系统，该系统包括一个33×33的高纯锗探测器阵列，该阵列耦合到一个非准直的传统闪烁相机。用该系统获得的投影图像的累积信噪比预计将比用常规伽马相机在20厘米直径×20厘米高的圆柱体中成像均匀分布的Tc-99m源所获得的投影图像高约4倍(灵敏度约高15倍)。预计在断层图像中也会有类似的收益。
The detection and imaging characteristics of a new type of gamma camera for single photon emission computed tomography have been investigated. Unlike conventional gamma cameras which use mechanical collimation, the new gamma camera utilizes electronic collimation which is obtained from a sequential interaction of gamma radiation with a dual position-and-energy sensitive detection system. Coincident counting between the two detectors provides localization of activity upon a multitude of conical surfaces throughout the object, wherefrom the three-dimensional activity distribution can be reconstructed. Not only does electronic collimation provide simultaneous multiple views of the object, but a large gain in sensitivity is also indicated over a conventionally collimated gamma camera under conditions of similar spatial resolution. Detector optimization studies have been performed to design a prototype system comprising a 33 X 33 array of high-purity germanium detectors coupled to an uncollimated conventional scintillation camera. The cumulative signal-to-noise ratio in projection images obtained with this system is expected to be about a factor of 4 higher (sensitivity about a factor of 15 higher) than that obtained in a corresponding projection image with a conventional gamma camera for imaging a uniformly distributed Tc-99m source in a 20-cm-diam X 20-cm-tall cylinder. A similar gain is expected in the tomographic images.