基于PFDK重建算法的工业CT转台单侧多次偏置锥束重建算法  

A PFDK-based reconstruction algorithm for industrial CT with multiple cone-beam scans of off-centered rotation

作　　者：陈云斌[1,2] 李寿涛 金晓 CHEN Yunbin;LI Shoutao;JIN Xiao(Institute of Applied Electronics,CAEP,Mianyang 621900,China;National X-ray Digital Imaging Instrument Centre,Mianyang 621000,China)

机构地区：[1]中国工程物理研究院应用电子学研究所,四川绵阳621900 [2]国家X射线数字化成像仪器中心,四川绵阳621000

出　　处：《中国体视学与图像分析》2020年第3期224-233,共10页Chinese Journal of Stereology and Image Analysis

摘　　要：转台单次多次偏置锥束扫描可以持续扩大锥束CT的扫描视野,针对这种扫描模式,本文提出了一种基于PFDK的转台单侧多次偏置锥束重建算法。首先,将转台在不同位置处采集的锥束投影重排为倾斜平行束投影;其次,再将分段倾斜平行束投影插值为完整的倾斜平行束投影;再次,再根据倾斜平行束投影数据的冗余性,对投影数据进行归一化加权;最后,采用PFDK重建算法得到重建图像。本文采用转台单侧三次偏置扫描技术,实现了直径超过1500 mm的扫描视野,并采用本文提出的重建算法获得了准确的三维体积图像。另外,本文从理论上分析了该算法在余弦加权、反投影步骤的误差特性。A cone beam multi-scan CT with off-centered rotation can successively enlarge the field of view of ICT.For this CT imaging model,a new type of reconstruction algorithm based on PFDK is proposed in this paper.In our method,cone beam projections acquired at various positions of rotation table are firstly rebinned into tilted parallel projections.Then,sections of tilted parallel projections are patched together to constitute complete parallel tilted projections.They are further weighted for data normalization based on redundant analysis.Finally,images are reconstructed by a PFDK reconstruction algorithm.An experiment with three scans of off-centered rotation and translation is conducted in this paper.The diameter of field of view is more than 1500 mm.The experimental result shows that the method proposed in this paper can get accurate reconstructions with the field of view enlarged.In addition,errors from cosine weighting and back projection are analyzed theoretically in this paper.

关 键 词：工业CT 锥束扫描 转台多次偏置 重排 PFDK重建 

分 类 号：TP391.41[自动化与计算机技术—计算机应用技术]