一种改进的锥束螺旋CT单层重排重建算法(英文)  

An Improved Single-Slice Rebinning Algorithm for Helical Cone-Beam CT

作　　者：陈炼[1] 吴志芳[1] 周立业[1] 

机构地区：[1]清华大学核能与新能源研究院,北京100084

出　　处：《CT理论与应用研究（中英文）》2008年第1期7-13,共7页Computerized Tomography Theory and Applications

摘　　要：多层螺旋CT中,采用大螺距可以大大提高扫描速度,在工业和医学中颇受青睐。但在给定探测器尺寸条件下,螺距过大会出现明显的伪影。Noo等1999年提出的单层重排算法(SSRB)能够适应较大的螺距,且有较高的重建图像质量。本文采用新的重排方法对SSRB算法进行了改进,理论分析及仿真实验表明,相同探测器大小时,改进的SSRB算法(ISSRB)可适用的螺距是SSRB的(1+tan^2δ)倍(δ射线源半张角),且有相近或更高的图像质量。Large pitch was used to speed up scanning in helical cone-beam CT, but its reconstruction remains a challenging problem. The Single-Slice ReBinning method （SSRB）, proposed by Noo et al, can obtain high image quality at large pitch, but artifacts appear when pitch is too large for given detector. In this paper, a new approximate reconstruction scheme, i.e. Improved Single-Slice ReBinning method （ISSRB） is described. It modified the key rebinning step of SSRB. Theoretical considerations and reconstruction of simulation data are presented in comparison to SSRB in the paper. Results show that the pitch of proposed method is （1＋tan^2δ） times larger than that of SSRB for given detector size, and the reconstruction image quality is comparable or even better.

关 键 词：锥束CT 单层重排 螺距 图像质量 

分 类 号：TP391.41[自动化与计算机技术—计算机应用技术]