非局部平均迭代修正的稀疏角度CT凸集投影重建  

Sparse angular CT projection onto convex set reconstruction using nonlocal means iterative modification

作　　者：刘楠[1] 黄静[1] 马建华[1] 路利军[1] 冯前进[1] 陈武凡[1] 

机构地区：[1]南方医科大学生物医学工程学院医学信息研究所,广东广州510515

出　　处：《南方医科大学学报》2010年第10期2224-2228,共5页Journal of Southern Medical University

基　　金：国家973项目(2010CB73503);国家自然科学基金(81000613)~~

摘　　要：鉴于非局部平均(nonlocal means,NL-means)滤波后的图像质量大幅提升,本文提出一种非局部平均迭代修正的稀疏角度CT凸集投影(projection onto convex set,POCS)重建方法。新方法采用两相式重建策略:首先对CT稀疏投影数据采用POCS算法进行重建,以获得满足数据一致性及非负性约束的重建图像;随后由POCS重建图像导引非局部平均对其进行优化修正,以消除图像中的高频噪声,保持图像边缘,减少条形伪影,达到提升图像质量的目的。两相交替进行,直至满足某一终止准则。仿真实验表明,本文提出的非局部平均迭代修正稀疏角度CTPOCS重建算法,可有效抑制重建图像噪声和条形伪影,大幅提高重建图像质量。Based on the fact that nonlocal means（NL-means） filtered image can likely produce an acceptable priori solution,we propose a sparse angularCT projection onto convex set（POCS） reconstruction using NL-means iterative modification.The new reconstruction scheme consists of two components,POCS and NL-means filter.In each phase of the sparse angularCT iterative reconstruction,we first used POCS algorithm to meet the identity and non-negativity of projection data,and then performed NL-means filter to the image obtained by POCS method for image quality improvement.Simulation experiments showed that the proposed POCS scheme can significantly improve the quality of sparse angular CT image by suppressing the noise and removing the streak-artifacts.

关 键 词：稀疏角度CT 凸集投影算法 非局部平均算法 迭代修正 

分 类 号：TP391.41[自动化与计算机技术—计算机应用技术]