Maximum-likelihood transmission image reconstruction for overlapping transmission beams
Maximum-likelihood transmission image reconstruction for overlapping transmission beams
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DOI：
10.1109/42.896785
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发表时间：
2000-11-01
影响因子：
10.6
通讯作者：
Ficaro, EP
中科院分区：
文献类型：
--
作者：
Yu, DF;Fessler, JA;Ficaro, EP
在许多透射成像几何结构中，透射的光子“光束”在检测器上重叠，使得检测器元件可以记录源自不同源或源位置并因此穿过物体的不同路径的光子。示例包括基于扫描线源或多个平行棒源的系统。传统的分析重建方法以及先前的统计重建方法都忽略了这些光束的重叠。我们提出了一种用于衰减图统计图像重建的新算法，该算法明确地考虑了传输扫描中的重叠光束，该算法保证在每次迭代时单调增加目标函数。该算法的可用性使得可以故意增加光束重叠以提高计数率。基于多线源阵列的模拟单光子发射断层扫描传输扫描表明，所提出的方法相对于“传统”重建算法（统计和非统计）产生了改进的分辨率/噪声权衡。
In many transmission imaging geometries, the transmitted "beams" of photons overlap on the detector, such that a detector element may record photons that originated in different sources or source locations and thus traversed different paths through the object. Examples include systems based on scanning line sources or on multiple parallel rod sources. The overlap of these beams has been disregarded by both conventional analytical reconstruction methods as well as by previous statistical reconstruction methods. We propose a new algorithm for statistical image reconstruction of attenuation maps that explicitly accounts for overlapping beams in transmission scans, The algorithm is guaranteed to monotonically increase the objective function at each iteration. The availability of this algorithm enables the possibility of deliberately increasing the beam overlap so as to increase count rates. Simulated single photon emission tomography transmission scans based on a multiple line source array demonstrate that the proposed method yields improved resolution/noise tradeoffs relative to "conventional" reconstruction algorithms, both statistical and nonstatistical.