计算机工程与应用 ›› 2023, Vol. 59 ›› Issue (18): 242-248.DOI: 10.3778/j.issn.1002-8331.2206-0348

• 图形图像处理 • 上一篇    下一篇

基于低维流形先验的低剂量CT重建方法

牛善洲,梁礼境,李硕,张梦真,邱洋,刘汉明,李楠   

  1. 1.赣南师范大学 数学与计算机科学学院,江西 赣州 341000
    2.赣南师范大学 赣州市计算成像重点实验室,江西 赣州 341000
    3.赣南师范大学 经济管理学院,江西 赣州 341000
  • 出版日期:2023-09-15 发布日期:2023-09-15

Low-Dose CT Reconstruction Using Low-Dimensional Manifold Prior

NIU Shanzhou, LIANG Lijing, LI Shuo, ZHANG Mengzhen, QIU Yang, LIU Hanming, LI Nan   

  1. 1.School of Mathematics and Computer Science, Gannan Normal University, Ganzhou, Jiangxi 341000, China
    2.Ganzhou Key Laboratory of Computational Imaging, Gannan Normal University, Ganzhou, Jiangxi 341000, China
    3.School of Economics and Management, Gannan Normal University, Ganzhou, Jiangxi 341000, China
  • Online:2023-09-15 Published:2023-09-15

摘要: 针对低剂量CT成像问题,提出了一个基于低维流形先验的低剂量CT重建方法。对投影数据进行统计建模,将低维流形正则化作为先验信息引入到投影数据恢复过程中,从而达到抑制噪声的目的,再使用传统的滤波反投影(filtered back-projection,FBP)算法进行CT图像重建。在Shepp-Logan体膜实验新方法重建结果与FBP、PWLS-QM(penalized weighted least-squares via quadratic?membrane)以及PWLS-DL(penalized weighted least-squares via dictionary learning)方法重建结果相比,相对均方根误差分别降低了64.87%、54.81%和7.02%;结构相似性指标分别提高了16.78%、1.88%和1.91%。在XCAT体膜实验中,新方法重建结果与FBP、PWLS-QM以及PWLS-DL方法重建结果相比,相对均方根误差分别降低了37.46%、22.17%和11.48%;结构相似性指标分别提高了3.33%、0.73%和1.22%。在临床数据实验中,新方法重建结果与FBP、PWLS-QM以及PWLS-DL方法重建结果相比,相对均方根误差分别降低了45.96%、25.61%和15.87%;结构相似性指标分别提高了19.12%、7.46%和8.63%。仿真和临床数据实验结果表明,新方法在有效抑制低剂量CT图像中噪声和伪影同时,可以很好地保持图像的结构信息和空间分辨率。

关键词: 低剂量CT, 图像重建, 投影数据恢复, 惩罚加权最小二乘, 低维流形先验

Abstract: In this paper, a low-dose CT reconstruction method using the low-dimensional manifold prior is presented. Incorporating with the low-dimensional manifold prior, a penalty weighted least-squares(PWLS-LDMM) approach is presented to reduce the noise in projection(sinogram) domain, and then the image is reconstructed by filtered back-projection(FBP) algorithm. The relative root mean square errors of Shepp-Logan image reconstructed by PWLS-LDMM method are reduced by 64.87%, 54.81% and 7.02%, respectively, as compared with that of FBP, PWLS-QM and PWLS-DL methods. The structural similarity values of Shepp-Logan image reconstructed by PWLS-LDMM method are increased by 16.78%, 1.88% and 1.91%, respectively, as compared with that of FBP, PWLS-QM and PWLS-DL methods. The relative root mean square errors of XCAT image reconstructed by PWLS-LDMM method are reduced by 37.46%, 22.17% and 11.48%, respectively, as compared with that of FBP, PWLS-QM and PWLS-DL methods. The structural similarity values of XCAT image reconstructed by PWLS-LDMM method are increased by 3.33%, 0.73% and 1.22%, respectively, as compared with that of FBP, PWLS-QM and PWLS-DL methods. The relative root mean square errors of clinical image reconstructed by PWLS-LDMM method are reduced by 45.96%, 25.61% and 15.87%, respectively, as compared with that of FBP, PWLS-QM and PWLS-DL methods. The structural similarity values of clinical image reconstructed by PWLS-LDMM method are increased by 19.12%, 7.46% and 8.63%, respectively, as compared with that of FBP, PWLS-QM and PWLS-DL methods. The simulation and clinical data empirical results demonstrate that the new method can effectively suppress the noise and artifacts in low-dose CT images, and maintain the image structure information and spatial resolution.

Key words: low-dose CT, image reconstruction, projection restoration, penalized weighted-least squares, low-dimensional manifold prior