Computer Engineering and Applications ›› 2007, Vol. 43 ›› Issue (32): 201-203.

• 工程与应用 • Previous Articles     Next Articles

OSEM reconstruction algorithm of cone-beam CT based on image block

ZENG Li1,2,JI Dong-jiang2,ZOU Xiao-bing2   

  1. 1.ICT Research Center,Key Lab. of Opt. Tech. and Sys. of the Education Ministry of China,Chongqing University,Chongqing 400044,China
    2.College of Mathematics and Physics,Chongqing University,Chongqing 400044,China
  • Received:1900-01-01 Revised:1900-01-01 Online:2007-11-11 Published:2007-11-11
  • Contact: ZENG Li

锥束CT的图像分块OSEM重建算法

曾 理1,2,冀东江2,邹晓兵2   

  1. 1.重庆大学 光电技术及系统教育部重点实验室ICT研究中心,重庆 400044
    2.重庆大学 数理学院,重庆 400044
  • 通讯作者: 曾 理

Abstract: In computed tomography,OSEM(Ordered Subsets Expectation Maximization) has good reconstructed image quality and costs less computation time.When there are noises in projection data,the image quality and convergence are influenced by the different subsets of projective orientation.To three dimensional cone beam CT,OSEM reconstruction algorithm with varied subsets based on image block is researched,the new means partition the image space into equal parts,then for different block image with varied subsets to reconstruct image after each iteration.Computer simulation experiment results show that,in cone-beam CT image reconstruction,this means can improve the convergence speed of image reconstruction and reduce the effect coming from the noise.

Key words: cone-beam CT, OSEM algorithm, image block, image reconstruction, computer simulation

摘要: 在计算机断层成像(CT)中,有序子集最大期望值算法(OSEM)能够在较短的时间内重建出高质量的图像。对含有噪声的投影数据,投影旋转分度子集划分的不同会影响到图像的重建质量和收敛速度。针对三维锥束CT情况,研究了一种基于图像分块的变子集OSEM重建方法,该方法将图像空间分割成等大小的图像块,然后在迭代过程中,对于不同的图像块用变化的子集进行图像重建。计算机仿真实验表明:该方法在锥束CT图像重建中,能够在抑制噪声的同时提高重建图像的收敛速度。

关键词: 锥束CT, OSEM 算法, 图像分块, 图像重建, 计算机仿真