基于混合滤波的避投影数据微分螺旋锥束CT重建  

Elimination of direct derivative of the projection data for image reconstruction based on hybrid filter in helical cone-beam CT

作　　者：马建华[1] 陈凌剑[1] 颜刚[1] 陈武凡[1] 

机构地区：[1]南方医科大学生物医学工程学院,广东广州510515

出　　处：《南方医科大学学报》2008年第6期911-914,共4页Journal of Southern Medical University

基　　金：国家973重点基础研究发展规划项目(2003CB716101)~~

摘　　要：目的本文将综合现有经典CT重建算法的优点,提出一种新的基于Hilbert-Ramp混合滤波的避投影数据微分螺旋锥束CT优质重建算法。方法新算法采用Katsevich算法框架,将现有FDK类型算法和Katsevich算法的不同优点有机地融合,完全回避投影数据中关于探测器坐标变量的直接微分运算。结果实验结果表明本文提出的新算法理论分析的正确性,有效地提高了螺旋锥束CT重建图像的分辨率,减少了重建伪影。结论文中提出的基于Hilbert-Ramp混合滤波的避投影数据微分螺旋锥束CT重建公式是对Katsevich重建公式的重要改进,同时Ramp滤波的引入可以针对不同的临床应用进行优化设计。Objective We present an alternative approach for precise reconstruction of the images from helical cone-beam projections combining Hilbert filter and Ramp filter. Methods Based on the Katsevich algorithm framework, the proposed algorithm combined the FDK-type algorithms and Katsevich algorithm for their respective advantages, to completely avoid the direct derivatives with respect to the coordinates on the detector plane. Results The experimental results validated the accuracy of the new algorithm, and this approach significantly improved the resolution of the reconstructed images with much reduced artifacts. Conclusions The proposed reconstruction formula based on hybrid Hilbert-Ramp filter is an important development of Katsevich reconstruction formula, and the different forms of the Ramp filters can be designed to realize frequency modulation according to the actual clinical application.

关 键 词：螺旋CT Hilbert滤波 Ramp滤波 优质重建 

分 类 号：R318[医药卫生—生物医学工程]