基于加权总差分最小化的中子稀疏投影计算机断层重建方法  

Neutron Computed Tomography Reconstruction Method Using Sparse Projections Based on Weighted Total Difference Minimization

作　　者：林强 杨民[1] 唐彬[2] 刘斌[2] 霍合勇[2] 刘家伟 Lin Qiang;Yang Min;Tang Bin;Liu Bin;Huo Heyong;Liu Jiawei(School of Mechanical Engineering and Automation ,Beijing University of Aeronautics and Astronautics,Beijing 100191,China;Institute of Nuclear Physics and Chemistry,China Academy of Engineering Physics,Mianyang,Sichuan 621900,China)

机构地区：[1]北京航空航天大学机械工程及自动化学院,北京100191 [2]中国工程物理研究院核物理与化学研究所,四川绵阳621900

出　　处：《光学学报》2019年第7期86-96,共11页Acta Optica Sinica

基　　金：国家自然科学基金(U1730116,11675012);核安全项目(41426020401)

摘　　要：为提升高噪声稀疏角度投影条件下中子计算机断层扫描(CT)质量,提出同时迭代重建方法(SIRT)与加权总差分最小化(WTDM)相结合的迭代重建方法(SIRT-WTDM)。在有无噪声情况下比较代数重建算法、联合代数重建算法及同时迭代重建算法的重建图像,证明了SIRT迭代重建具有较高的图像重建精度与较强的抗噪声性能,因此将SIRT作为高噪声中子投影图像CT迭代重建算法的保真项。考虑到对图像梯度稀疏性与连续性的约束,中子CT迭代重建方法的正则化约束项采用WTDM方法。由Shepp-Logan模体与真实冷中子层析扫描数据验证可知,在极端稀疏角度投影条件下,SIRT-WTDM可获得较好的重建效果。Aiming at improving the quality of the neutron computed tomography(CT) reconstructed from high noise and sparse angle projection data, an iterative reconstruction method(SIRT-WTDM) combined the simultaneous iterative reconstruction technique(SIRT) and weighted total difference minimization(WTDM) is successfully proposed. The reconstructed images obtained by algebraic reconstruction technique, simultaneous algebraic reconstruction technique, and SIRT are compared with or without the random noise in the projections, from which the SIRT method is proved to have higher reconstruction accuracy and stronger anti-noise ability. Therefore, the SIRT method is adopted as the fidelity term of the neutron CT iterative reconstruction method with high-noise projections. Considering the constraint to the sparsity and the continuity of the image gradient, the WTDM method is adopted as the regularization term of the neutron CT iterative reconstruction method. Under the condition of extreme sparse angle projections, the SIRT-WTDM can obtain the better reconstruction images, which has been proved by the Shepp-Logan simulated data and cold neutron CT scanning data.

关 键 词：成像系统 中子计算机断层成像 加权总差分最小化 稀疏角度投影 噪声抑制 

分 类 号：TP391.4[自动化与计算机技术—计算机应用技术]