基于半扇束扫描的CT图像迭代重建算法

为解决探测器尺寸受限导致的CT图像重建区域面积受限以及X射线辐射剂量较大问题,提出一种半扇束扫描模式下的CT图像迭代重建算法。该算法将探测器水平偏置,稀疏角度下采集物体投影数据,利用ART-TV迭代算法对投影数据进行重建,达到预设迭代次数后,输出重建图像。实验结果表明:半扫描可扩大重建面积,降低探测器成本;利用迭代重建算法,降低剂量的同时重建优质CT图像。

Iterative CT image Reconstruction Based on Half-Fan Scan

An iterative CT image reconstruction method based on half-fan scan is proposed to solve the prob-lems of limited field of view and over-usage of radiation dose. Firstly, detector array is placed horizontally. Secondly,projection data of object are sampled sparsely in a circular scan. Thirdly, the collected projection da-ta and reconstruct CT image by ART-TV reconstruction method are used. At last, output reconstructed image after the set number of iterations reaches. Experiments show that half-fan scan can double the field of view ap-proximately, and reduce the cost of detector. Additionally, radiation dose can be reduced by using sparse sam-pling and good-quality image is reconstructed by iterative image reconstruction.