基于正弦图恢复的CT局部重建算法  

CT Local Reconstruction Algorithm Based on Sinogram Restoration

作　　者：梁亚星 张萌 陈燕[2,3] 桂志国[1,2,3] 张权[1,2,3] LIANG Ya-xing;ZHANG Meng;CHEN Yan;GUI Zhi-guo;ZHANG Quan(National Key Laboratory for Electronic Measurement Technology,North University of China,Taiyuan 030051,China;Key Laboratory for Biomedical Imaging and Big Data of Shanxi Province,North University of China,Taiyuan 030051,China;School of Information and Communication Engineering,North University of China,Taiyuan 030051,China)

机构地区：[1]中北大学电子测试技术国家重点实验室,山西太原030051 [2]中北大学生物医学成像与影像大数据山西省重点实验室,山西太原030051 [3]中北大学信息与通信工程学院,山西太原030051

出　　处：《中北大学学报（自然科学版）》2020年第2期170-174,187,共6页Journal of North University of China(Natural Science Edition)

基　　金：国家自然科学基金(61671413,61801438);山西省自然科学基金项目(2015011046,201901D111153);电子测试技术重点实验室开放基金项目(ZDSYSJ2015006);中北大学青年学术带头人项目(QX201801);山西省青年科学基金(201801D221196)。

摘　　要：针对局部扫描过程中投影数据沿探测器方向截断的特点,提出一种基于正弦图数据恢复的扇束CT局部重建算法.算法首先基于截断正弦图提取的边缘信息对缺失投影数据进行扩充,接下来对未扩充完整的零值区域利用两侧已知的投影数据进行线性插值,最后依据扩充完整的投影数据经滤波反投影重建出局部图像.仿真和临床数据的重建结果表明,算法对直接利用局部截断投影数据重建图像中呈现的环形伪影有明显的抑制作用,且重建图像边缘清晰.Aiming at the truncation characteristics of projection data along the detector direction during local scanning,a CT local reconstruction algorithm based on sinogram data restoration was proposed.The algorithm firstly augments the missing projection data based on the edges extracted from the truncated sinogram.Then,the unexpanded complete zero-value region was linearly interpolated using the projection data on both sides.Finally,the local region of interest image was reconstructed by filtered back projection according to the expanded complete projection data.The reconstruction results of simulation and clinical data show that the algorithm has obvious inhibitory effect on the ring artifacts in the reconstructed image from the local truncated projection data not being augmented,and the edges of the reconstructed image are clear.

关 键 词：扇束CT 局部重建 截断正弦图 环状伪影 正弦图恢复 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]