Three-dimensional SPECT reconstruction of combined cone beam and parallel beam data.
Three-dimensional SPECT reconstruction of combined cone beam and parallel beam data.
复制标题
组合锥形束和平行束数据的三维 SPECT 重建。
DOI：
10.1088/0031-9155/37/3/003
复制
发表时间：
1992
影响因子：
3.5
通讯作者：
Coleman,RE
中科院分区：
文献类型：
--
作者：
Jaszczak,RJ;Li,J;Wang,H;Coleman,RE
与使用平行 (P) 孔准直的采集几何结构相比，使用锥形束 (CB) 准直的单光子发射计算机断层扫描 (SPECT) 表现出更高的灵敏度。然而，CB 准直的视场较小，可能会导致投影被截断和图像伪影。这项工作的主要目标是研究最大似然期望最大化 (ML-EM) 方法来重建同时采集的平行和锥形束 (P&CB) SPECT 数据。通过使用两个锥束准直器和一个平行孔准直器，可以使用商用三相机系统同时进行 P&CB 采集。整体灵敏度的损失（相对于使用三个 CB 准直器）约为 15% 至 20%。作者开发了三种使用改进的 ML-EM 算法组合 P&CB 数据的方法。第一种方法包括在每次迭代后使用 ML-EM 算法使用两个数据集重建单个中间图像。另外两种迭代算法结合了中间平行光束 (PB) 和 CB 源估计来提高图像质量。
Single photon emission computed tomography (SPECT) using cone beam (CB) collimation exhibits increased sensitivity compared with acquisition geometries using parallel (P) hole collimation. However, CB collimation has a smaller field-of-view which may result in truncated projections and image artifacts. A primary objective of this work is to investigate maximum likelihood-expectation maximization (ML-EM) methods to reconstruct simultaneously acquired parallel and cone beam (P&CB) SPECT data. Simultaneous P&CB acquisition can be performed with commercially available triple camera systems by using two cone-beam collimators and a single parallel-hole collimator. The loss in overall sensitivity (relative to the use of three CB collimators) is about 15 to 20%. The authors have developed three methods to combine P&CB data using modified ML-EM algorithms. The first method consists of using both data sets to reconstruct a single intermediate image after each iteration using the ML-EM algorithm. The other two iterative algorithms combine intermediate parallel beam (PB) and CB source estimates to enhance image quality.