中国组织工程研究

中国组织工程研究 ›› 2011, Vol. 15 ›› Issue (13): 2412-2415.doi: 10.3969/j.issn.1673-8225.2011.13.031

• 骨与关节图像与影像 bone and joint imaging • 上一篇    下一篇

一种快速校正CT环形伪影的方法

赖胜圣，彭胜华，余晓锷   

  1. 南方医科大学生物医学工程学院，广东省广州市510515
  • 收稿日期:2010-12-17 修回日期:2011-02-22 出版日期:2011-03-26 发布日期:2013-10-23
  • 通讯作者: 余晓锷，副教授，南方医科大学生物医学工程学院，广东省广州市510515 yxe@fimmu.com
  • 作者简介:赖胜圣★，1982年生，汉族，南方医科大学在读硕士，讲师，主要从事大型医疗设备的质量保证与教学。 laiss@gdyzy. edu.cn

A new method for quickly correcting ring artifacts in CT image

Lai Sheng-sheng, Peng Sheng-hua, Yu Xiao-e   

  1. School of Biomedical Engineering, Southern Medical University, Guangzhou  510515, Guangdong Province, China
  • Received:2010-12-17 Revised:2011-02-22 Online:2011-03-26 Published:2013-10-23
  • Contact: Yu Xiao-e, Associate professor, School of Biomedical Engineering, Southern Medical University, Guangzhou 510515, Guangdong Province, China yxe@fimmu.com
  • About author:Lai Sheng-sheng★, Studying for master’s degree, Lecturer, School of Biomedical Engineering, Southern Medical University, Guangzhou 510515, Guangdong Province, China laiss@gdyzy.edu.cn

PDF

682

被引次数

20

摘要：

背景：环形伪影严重影响了CT图像质量，对图像后处理造成困难以及容易造成误诊断。目前去除环形伪影必不可少。
目的：去除CT重建图像中的环形伪影，提高CT图像质量以及后续处理和量化分析的精度，便于诊断。
方法：首先把含环形伪影的CT图像进行线性变换，将灰度图像转换成浮点类型的图像。接着由直角坐标变换到极坐标，这样原来的环形伪影就被变换成线形伪影。设计多维滤波器，计算每个象素滤波后均值以及方差，通过与阈值比较确定伪影范围。最后通过对伪影范围进行修正以及对图像进行坐标变换，变为灰度图像。
结果与结论：通过Matlab 7.0软件设计程序，处理含环形伪影的CT图像。实验表明，此方法能有效快速地校正CT环形伪影，是一种属于图像后处理的校正方法。

关键词: 环形伪影, 校正, CT图像, 多维滤波器, 图像质量, 后处理

Abstract:

BACKGROUND: Ring artifacts, seriously affect the CT image quality, create difficulties to post-processing of the images, and easily lead to wrong diagnosis. At present, the removal of ring artifacts is essential.
OBJECTIVE: A new image correction method based on polar coordinate transformation is proposed to remove ring artifacts in CT image and to improve the precisions of post processing and quantitative analysis, as well as facilitate the diagnosis.
METHODS: Firstly, the CT images with ring artifacts were processed by linear transformation, converting the gray images into floating-point types of images. Secondly, the ring artifacts in the Cartesian coordinate were transformed into the vertical line artifacts in the polar coordinate. Thirdly, designing multidimensional filters, calculated the mean and variance of each pixel after filtering, compared with the threshold value to determine the scope of artifacts. Finally, correcting the range of artifacts, and converting into gray images by coordinate transformation.
RESULTS AND CONCLUSION: Designing program by Matlab 7.0, the experiment indicates that this method can correct ring artifacts in CT images quickly and effectively, and it is a image post-processing correction methods.

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