基于小波变换的锥束CT滤线栅条纹去除方法  

Removal of Gridline Artifacts in Cone-beam CT Based on Wavelet Transform

作　　者：王宇昂 高河伟[1] 张丽[1] WANG Yu’ang;GAO Hewei;ZHANG Li(Department of Engineering Physics,Tsinghua University,Beijing 100084,China)

机构地区：[1]清华大学工程物理系,北京100084

出　　处：《CT理论与应用研究（中英文）》2023年第4期437-449,共13页Computerized Tomography Theory and Applications

基　　金：国家自然科学基金(融合动态能谱与个性化建模的冠状动脉容积成像方法与关键技术(62031020))。

摘　　要：采用平板探测器的X射线锥束成像系统中,由于散射会带来图像伪影从而劣化图像质量,通常采用在平板探测器前安装滤线栅来去除散射,但滤线栅会在获取的图像上形成周期性的条状伪影,如何去除条状伪影是X射线锥束成像系统中的一个关键技术问题。本文对已有的滤线栅条纹去除方法进行概述,创新性地提出基于频谱拼接的小波变换方法,既能在损失物体细节信息少的前提下很好地去除滤线栅条纹,又不会引入小波变换谐波。通过实际实验,检验该方法的有效性。In cone-beam computed tomography with flat-panel imagers,scattered X-ray photons lead to reduced image quality.Insertion of an anti-scatter grid between the patient or object and the flat-panel imagers is one of the most used techniques for reducing scattered radiation.However,while the scatter is reduced,gridline artifacts can be visible.Suppressing gridline artifacts in cone-beam computed tomography is significant.In this paper,the existing methods of removing gridline artifacts are summarized.Moreover,the wavelet transform method based on spectrum coalescence is innovatively proposed for removing gridline artifacts.Wavelet transform can remove gridline artifacts effectively and without introducing wavelet transform harmonics thus reducing the loss of object details.The effectiveness of this method is verified by experiments.

关 键 词：滤线栅条纹 小波变换 频谱拼接 

分 类 号：O242[理学—计算数学] TP391[理学—数学]