低剂量CT重建中的双边滤波权值优化新方法  

Bilateral filtering weights optimization in low-dose computed tomography image reconstruction

作　　者：李凯旋[1] 黄静[1] 马建华[1] 田玲玲[1] 张华[1] 路利军[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：《电路与系统学报》2012年第2期95-99,94,共6页Journal of Circuits and Systems

基　　金：国家自然科学基金项目(81000613;81101046);国家科技支撑计划项目(2011BAI12B03);广东省科技计划项目(2011A030300005);国家973项目(2010CB732503)

摘　　要：为了提升低剂量CT重建图像质量,本文提出了一种基于投影数据恢复导引的双边滤波权值优化方法。新方法有效地将CT投影数据恢复和图像数据恢复的两种低剂量成像策略进行结合,实现优质的低剂量CT重建。具体而言,本文中投影数据恢复采用三维块匹配滤波进行,图像数据恢复采用双边滤波进行,其中双边滤波权值进行优化设计。在双边滤波权值设计中,首先利用投影数据的三维块匹配滤波数据获得FBP重建图像,然后利用该FBP图像引导双边滤波权值的优化设计。最终的重建图像则经基于优化权值的双边滤波来恢复直接的低剂量FBP重建图像来完成。仿真和临床实验表明,本文方法在噪声消除,伪影抑制和细节保持方面均有良好效果。To achieve high-quality low-dose CT image reconstruction in this paper, a projection data restoration based bilateral filtering weights optimization scheme is proposed, by taking both advantages of the projection restoration and image restoration methods. Specifically, the presented method is first to restore the low-dose projection by using a block-matching and 3D （BM3D） filtering algorithm; then following the restored projection, sectional image is reconstructed by using a filtered back-projection （FBP） algorithm and the associated image is used to optimize weights of bilateral filtering; finally, using the bilateral filtering with the optimized weights to restore the direct FBP reconstructed image from the raw low-dose projection. Simulated and clinical experimental results demonstrate that the presented algorithm performs well in lowering the noise, preserving the image edge and details than other methods.

关 键 词：低剂量CT 投影数据恢复 图像数据恢复 BM3D滤波 双边滤波 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]