Mueller K, Yagel R, Cornhill J F
IEEE Trans Med Imaging. 1997 Apr;16(2):223-30. doi: 10.1109/42.563668.
The order in which the projections are applied in the algebraic reconstruction technique (ART) has a great effect on speed of convergence, accuracy, and the amount of noise-like artifacts in the reconstructed image. In this paper, a new projection ordering scheme for ART is presented: the weighted-distance scheme (WDS). It heuristically optimizes the angular distance of a newly selected projection with respect to an extended sequence of previously applied projections. This sequence of influential projections may incorporate the complete set of all previously applied projections or any limited time interval subset thereof. The selection algorithm results in uniform sampling of the projection access space, minimizing correlation in the projection sequence. This produces more accurate images with less noise-like artifacts than previously suggested projection ordering schemes.
在代数重建技术（ART）中应用投影的顺序对收敛速度、准确性以及重建图像中类噪声伪影的数量有很大影响。本文提出了一种用于ART的新投影排序方案：加权距离方案（WDS）。它启发式地优化新选择投影相对于先前应用投影的扩展序列的角距离。这个有影响的投影序列可以包含所有先前应用投影的完整集合或其任何有限时间间隔子集。选择算法导致投影访问空间的均匀采样，使投影序列中的相关性最小化。与先前提出的投影排序方案相比，这产生了噪声伪影更少的更准确图像。
