CAJ | 학술논문

低剂量CT重建已成为当前X-线CT成像的研究热点。针对低剂量CT成像，本文提出一种改进的先验图像约束的压缩感知重建方法。新方法首先对CT线积分投影数据采用惩罚加权最小二乘方法进行降噪恢复，接着对恢复后的投影数据进行滤波反投影重建，然后以重建图像作为先验图像应用先验图像约束的压缩感知方法进行统计迭代重建。实验结果表明，同已有的先验图像约束的压缩感知重建方法相比，新方法能够更有效地抑制低剂量CT重建图像中的噪声和条形伪影，同时较好地保持图像的空间分辨率。
저제량CT중건이성위당전X-선CT성상적연구열점。침대저제량CT성상，본문제출일충개진적선험도상약속적압축감지중건방법。신방법수선대CT선적분투영수거채용징벌가권최소이승방법진행강조회복，접착대회복후적투영수거진행려파반투영중건，연후이중건도상작위선험도상응용선험도상약속적압축감지방법진행통계질대중건。실험결과표명，동이유적선험도상약속적압축감지중건방법상비，신방법능구경유효지억제저제량CT중건도상중적조성화조형위영，동시교호지보지도상적공간분변솔。
Low-dose computed tomography (CT) reconstruction has become the focus of X-ray CT imaging study. In this paper, we propose an improved prior image constrained compressed sensing (PICCS) reconstruction approach. A penalized weighted least-squares approach was adopted to realize the line integral projection (sinogram) data restoration, followed by filtered back-projection (FBP) of the restored sinogram data for image reconstruction. Finally, the FBP image as the prior image was used for PICCS approach for dose reduction. Qualitative and quantitative evaluations were carried out with computer simulation. The results showed that the present approach yielded noticeable gains over the original PICCS approach for dose reduction in terms of noise-induced artifacts suppression and edge detail preservation.