基于三维加权和双域滤波的螺旋CT伪影校正  

Helical CT Artifact Correction Based on 3D Weighting and Dual Domain Filtering

作　　者：牛晓伟 孔慧华[1,2] 邸云霞 NIU Xiaowei;KONG Huihua;DI Yunxia(School of Mathematics,North University of China,Taiyuan 030051,China;Shanxi Provincial Key Laboratory of Signal Capturing and Processing,North University of China,Taiyuan 030051,China)

机构地区：[1]中北大学数学学院,太原030051 [2]信息探测与处理山西省重点实验室,太原030051

出　　处：《计算机测量与控制》2023年第1期246-251,共6页Computer Measurement &Control

基　　金：国家自然科学基金(61801437,61871351,61971381);山西省基础研究计划资助项目(202103021224190)。

摘　　要：螺旋CT重建会受到锥束伪影和风车伪影的影响,锥束伪影是由于锥角和螺距过大而导致的,而风车伪影由纵向方向采样不足引起,为了降低锥束伪影与风车伪影对CT图像的影响,提出一种螺旋CT伪影校正算法;首先采用三维加权螺旋FDK算法进行重建,有效去除重建图像中的锥束伪影,然后采用改进的双域滤波算法对含风车伪影图像进行校正;三维加权螺旋FDK算法通过对大锥角的射线给予不利权重来抑制锥束伪影,改进的双域滤波算法可以在去除风车伪影的同时保留更多的细节;计算机仿真实验结果表明,该算法能有效地抑制重建图像中的锥束伪影和风车伪影,提高CT图像的质量。Helical CT reconstruction is affected by the artifacts of cone beam and windmill, cone beam artifacts are caused by excessive cone angle and pitch, and windmill artifacts by insufficient sampling in the longitudinal direction. In order to reduce the effects of cone beam artifacts and windmill artifacts on CT images, a helical CT artifact correction algorithm is proposed;Firstly, a 3D weighted helical FDK algorithm is used for the reconstruction to effectively remove cone beam artifacts from the reconstructed images. Then an improved dual-domain filtering algorithm is used to correct the images containing windmill artifacts;The 3D weighted helical FDK algorithm suppresses cone beam artifacts by using unfavorable weights to rays with large cone angles, and the improved dual-domain filtering algorithm can preserve more details while removing windmill artifacts;The simulation results show that the algorithm can effectively suppress cone beam artifacts and windmill artifacts in the reconstructed images, which improves the quality of CT images.

关 键 词：螺旋CT 三维加权 双域滤波 锥束伪影 风车伪影 

分 类 号：TP391.41[自动化与计算机技术—计算机应用技术]