基于不规则螺旋扫描CT图像重建算法的研究  

Image reconstruction algorithm for irregular spiral CT scanning

作　　者：蔚慧甜[1] 

机构地区：[1]中北大学信息探测与处理技术研究所,山西太原030051

出　　处：《传感器世界》2011年第8期18-20,23,共4页Sensor World

摘　　要：锥束螺旋CT可以解决长物体的检测问题,目前广泛应用的锥束螺旋CT主要采用螺旋FDK算法进行图像重建,近年来为了使算法能更应用于实际,许多学者对标准的螺旋轨迹进行了拓展。针对这一情形,本文提出了变螺距不规则螺旋扫描轨迹,变螺距螺旋扫描可根据目标物体形状的变化,随时做出调整以获得最佳的图像重建质量,有更快的扫描速度和更高的时间、空间分辨率。本文首先设计了两种随投影角度自适应变化的变螺距螺旋轨迹函数,然后采用近似FDK重建算法进行重建。仿真结果表明,变螺距螺旋FDK重建算法能够重建出较好的图像质量,本文的研究可以促进实用变螺距螺旋锥束CT的发展。Cone-beam spiral CT can be used to solve the problem of long-object detection. At present, FDK algorithm is widely used for image reconstruction of cone-beam spiral CT. Recently, to make the algorithm more practical, many other non-standard spiral trajectories have been proposed. In response to this situation, the irregular spiral scan of variable pitch is proposed. Variable pitch spiral scan can change shape depending on the target object, improve the scanning speed, and have higher time and space resolution. In this paper, two variable pitch helical trajectory functions are designed firstly ,which change with the projection angle adaptively. And then approximate reconstruction algorithm--FDK reconstruction algorithm is used to reconstruct images. The simulation results show that FDK reconstruction algorithm for variable pitch helical can rebuild images with better quality. The work in this paper may facilitate developments of practical variable pitch helical cone-beam CT .

关 键 词：CT 变螺距螺旋扫描 FDK重建算法 卷积 

分 类 号：TP391.41[自动化与计算机技术—计算机应用技术]