基于圆扫描轨迹的锥形束CT重建与环形伪影消除  

Cone-beam CT reconstruction based on circular scan trajectory and ring artifact reduction

作　　者：杨俊[1,2] 甄鑫[1] 卢文婷[1] 周凌宏[1] 

机构地区：[1]南方医科大学生物医学医学工程学院,广东广州510515 [2]解放军第458医院,广东广州510602

出　　处：《南方医科大学学报》2009年第12期2379-2382,共4页Journal of Southern Medical University

基　　金：国家自然科学基金(30970866);广东省教育厅学科建设基金(CGZHZD0713);广东省重点科技计划(2008A030102011)

摘　　要：FDK算法由于其数学表达简单,实现简单、快速,是目前基于圆扫描轨迹的锥形束CT(Cone-beam CT,CBCT)重建的主流算法。但CBCT采集系统固有的机械误差和在大锥角的情况下,重建图像会引入各种伪影。本文利用体模投影图像、老鼠投影数据和VARIAN23EX医用直线加速器采集的真实人体投影数据对FDK算法进行了验证,并提出了一种快速精确消除重建后图像环形伪影的方法,该方法能精确的定位出环形伪影,并不受环形伪影宽度大小的约束,能最大限度的保全原有图像信息。The FDK algorithm is one of the most widely used algorithms for cone-beam CT reconstruction in circular trajectory due to its simplicity of implementation and computational efficiency. However, the images reconstructed by the FDK algorithm based on real projection data may be blurred without electronic correction and geometric calibration, and are often plagued by deleterious ring artifacts and shading artifacts. We compared the images reconstructed with and without detector correction based on computer experiment of the real biological object. The experimental simulation shows that these algorithms are effective in reducing the ring artifact without compromising the image resolution, and produce satisfactory results.

关 键 词：环形伪影 伪影消除 CT重建 锥形 扫描 医用直线加速器 采集系统 重建图像 

分 类 号：TP391.41[自动化与计算机技术—计算机应用技术]