Zeng Gengsheng L
Department of Engineering, Weber State University, Ogden, Utah 84408, United States of America.
Department of Radiology and Imaging Sciences, University of Utah, Salt Lake City, Utah 84108, United States of America.
Biomed Phys Eng Express. 2019 Apr;5(3). doi: 10.1088/2057-1976/ab0926. Epub 2019 Mar 12.
Green's one-step-late (OSL) algorithm is a popular image reconstruction algorithm in emission-data tomography, in spite of its convergence issues. One drawback of Green's algorithm is that the algorithm exhibits non-stationary regularization when the algorithm's projector and backprojector model the attenuation effects in single photon emission computed tomography (SPECT). This paper suggests a remedy to improve Green's OSL algorithm so that stationary regularization can be obtained. This paper also observes some similarities between the modified Green's OSL algorithm and the gradient descent algorithm.
格林的一步延迟(OSL)算法是发射数据断层扫描中一种流行的图像重建算法,尽管它存在收敛问题。格林算法的一个缺点是,当该算法的投影器和反投影器对单光子发射计算机断层扫描(SPECT)中的衰减效应进行建模时,该算法会表现出非平稳正则化。本文提出了一种改进格林OSL算法的补救方法,以便能够获得平稳正则化。本文还观察到改进后的格林OSL算法与梯度下降算法之间的一些相似之处。