利用投影数据的有序子集进行加速图像重建。

Accelerated image reconstruction using ordered subsets of projection data.

机构信息

Dept. of Stat., Macquarie Univ., North Ryde, NSW.

出版信息

IEEE Trans Med Imaging. 1994;13(4):601-9. doi: 10.1109/42.363108.

Abstract

The authors define ordered subset processing for standard algorithms (such as expectation maximization, EM) for image restoration from projections. Ordered subsets methods group projection data into an ordered sequence of subsets (or blocks). An iteration of ordered subsets EM is defined as a single pass through all the subsets, in each subset using the current estimate to initialize application of EM with that data subset. This approach is similar in concept to block-Kaczmarz methods introduced by Eggermont et al. (1981) for iterative reconstruction. Simultaneous iterative reconstruction (SIRT) and multiplicative algebraic reconstruction (MART) techniques are well known special cases. Ordered subsets EM (OS-EM) provides a restoration imposing a natural positivity condition and with close links to the EM algorithm. OS-EM is applicable in both single photon (SPECT) and positron emission tomography (PET). In simulation studies in SPECT, the OS-EM algorithm provides an order-of-magnitude acceleration over EM, with restoration quality maintained.

摘要

作者为标准算法（如期望最大化（EM））定义了有序子集处理，以从投影中恢复图像。有序子集方法将投影数据分组为有序的子集（或块）序列。有序子集 EM 的一次迭代定义为通过所有子集的单次遍历，在每个子集中使用当前估计值来初始化使用该数据子集的 EM 应用。这种方法在概念上类似于 Eggermont 等人（1981 年）引入的用于迭代重建的块-Kaczmarz 方法。同时迭代重建（SIRT）和乘法代数重建（MART）技术是众所周知的特殊情况。有序子集 EM（OS-EM）提供了一种恢复方法，施加了自然的正定性条件，并与 EM 算法密切相关。OS-EM 可同时应用于单光子发射计算机断层扫描（SPECT）和正电子发射断层扫描（PET）。在 SPECT 的模拟研究中，OS-EM 算法提供了比 EM 大一个数量级的加速，同时保持了恢复质量。