波谱学杂志 ›› 2017, Vol. 34 ›› Issue (3): 294-301.doi: 10.11938/cjmr20162525

• 研究论文 • 上一篇    下一篇

基于局部位移校正的磁共振图像相干平均

李文静1, 谢海滨1,2, 严序3, 周敏雄4, 向之明5, 杨光1,2   

  1. 1. 华东师范大学 物理与材料科学学院, 上海市磁共振重点实验室, 上海 200062;
    2. 上海卡勒幅磁共振技术有限公司, 上海 201614;
    3. 西门子医疗东北亚科研合作部, 上海 201318;
    4. 上海健康医学院, 上海 201318;
    5. 广州市番禺区中心医院放射科, 广东 广州 511400
  • 收稿日期:2016-05-03 修回日期:2017-07-17 出版日期:2017-09-05 发布日期:2017-09-05
  • 通讯作者: 谢海滨,Tel:021-62233873,E-mail:hbxie@phy.ecnu.edu.cn;杨光,Tel:021-62233873,E-mail:gyang@phy.ecnu.edu.cn. E-mail:hbxie@phy.ecnu.edu.cn;gyang@phy.ecnu.edu.cn
  • 基金资助:
    国家高技术研究发展计划("863"计划)资助项目(2014AA123400).

Magnetic Resonance Image Averaging with Local Offset Correction

LI Wen-jing1, XIE Hai-bin1,2, YAN Xu3, ZHOU Min-xiong4, XIANG Zhi-ming5, YANG Guang1,2   

  1. 1. Shanghai Key Laboratory of Magnetic Resonance, Department of Physics, East China Normal University, Shanghai 200062, China;
    2. Shanghai Colorful Magnetic Resonance Technology Co. Ltd., Shanghai 201614, China;
    3. MR Collaboration NE Asia, Siemens Healthcare, Shanghai 201318, China;
    4. Shanghai University of Medicine & Health Sciences, Shanghai 201318, China;
    5. Department of Radiology, Panyu Center Hospital of Guangzhou, Guangzhou 511400, China
  • Received:2016-05-03 Revised:2017-07-17 Online:2017-09-05 Published:2017-09-05

摘要: 多次扫描相干平均是提高磁共振图像信噪比的常用方法,但如果在多次扫描过程中病人发生自主或不自主的运动,使得图像中的组织发生位移,简单相干平均图像会导致图像模糊.本文受非局域均值算法的启发,提出了一种基于局部位移校正的相干平均方法.该算法通过比较多次采集的图像中组织结构的局部相似性,找出图像间的局部位移,利用该信息修正位移后进行加权平均,从而达到提高图像信噪比的目的.我们用模型及真实的肝脏弥散数据进行了实验.实验结果表明,对于不同次采样间存在运动的磁共振图像,该算法可有效地提高信噪比并保持结构边缘;其结果优于简单的相干平均,去噪效果也优于经典的非局域均值算法.

关键词: 磁共振成像(MRI), 非局域均值, 图像去噪, 相干平均

Abstract: In magnetic resonance imaging (MRI), data averaging is often used to improve signal-to-noise ratio (SNR) of the images. However, image blurring can be induced by averaging if movements occur during scanning. Inspired by the patch-matching method used in the non-local means algorithm, a new method to find out local offsets of structures in multiple images was proposed by comparing the neighborhood similarities of the image patches. The local offsets could then be corrected before weighted averaging of the images. The performance of the proposed method was verified with both phantom and patient images. The results demonstrated that the proposed algorithm could improve SNR while preserving the image edges and details correctly.

Key words: non-local means, image denoising, averaging, magnetic resonance imaging (MRI)

中图分类号: