东北大学学报（自然科学版）

东北大学学报:自然科学版 ›› 2020, Vol. 41 ›› Issue (7): 1048-1053.DOI: 10.12068/j.issn.1005-3026.2020.07.021

• 生物工程 • 上一篇    下一篇

永磁磁共振扩散加权平面回波成像涡流伪影校正

王艳飞1， 杨金柱2,3， 康雁1,4   

  1. (1.东北大学 医学与生物信息工程学院， 辽宁 沈阳110169; 2.东北大学 医学影像智能计算教育部重点实验室， 辽宁 沈阳110169；3.东北大学 计算机科学与工程学院， 辽宁 沈阳110169； 4.深圳技术大学 健康与环境工程学院， 广东 深圳518118)
  • 收稿日期:2019-09-27 修回日期:2019-09-27 出版日期:2020-07-15 发布日期:2020-07-15
  • 通讯作者: 王艳飞
  • 作者简介:王艳飞(1977-)，男，内蒙古赤峰人，东北大学博士研究生; 杨金柱(1977-)，男，内蒙古通辽人，东北大学教授，博士生导师; 康雁(1964-)，男，辽宁沈阳人，东北大学教授，深圳技术大学特聘教授，博士生导师.
  • 基金资助:
    国家自然科学基金青年基金资助项目(61602101).

Eddy Currents Artifacts Correction in Diffusion-Weighted Echo-Planar Imaging for Permanent MRI Scanner

WANG Yan-fei1， YANG Jin-zhu2,3， KANG Yan1,4   

  1. 1. College of Medicine and Biomedical Information Engineering， Northeastern University， Shenyang 110169， China; 2. Key Laboratory of Intelligent Computing in Medical Image， Ministry of Education， Northeastern University， Shenyang 110169， China; 3. School of Computer Science & Engineering， Northeastern University， Shenyang 110169， China; 4. College of Health Science and Environmental Engineering， Shenzhen Technology University， Shenzhen 518118， China.
  • Received:2019-09-27 Revised:2019-09-27 Online:2020-07-15 Published:2020-07-15
  • Contact: KANG Yan
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摘要： 研究了涡流对永磁磁共振扩散加权平面回波成像的影响，提出了一种针对永磁磁共振成像系统的涡流补偿算法，并对扩散加权EPI序列由于剩余涡流引起的相位误差提出了一种补偿方法.在0.35T永磁型磁共振成像系统上对算法进行了验证，不同的梯度方向经过涡流预加重补偿后，涡流最少也会降至未补偿前的1/15.对涡流补偿和未补偿的模体扩散加权EPI图像进行了比较，经过两次补偿后，图像几何畸变会降低5%，图像伪影会降低1/3.实验结果表明，所提出的算法可以有效抑制因涡流引起的扩散加权EPI伪影及畸变.

关键词: 磁共振成像, 平面回波成像, 扩散加权成像, 涡流, 预加重

Abstract: The effect of eddy currents on diffusion-weighted echo-planar imaging(EPI) was investigated for permanent magnetic resonance imaging(MRI) scanner. An automatic eddy currents calibration algorithm was presented， and a compensation method for phase errors caused by residual eddy currents in diffusion-weighted EPI was proposed. The method was tested and validated on a 0.35T permanent magnet MRI scanner.For three different gradient directions after pre-emphasis compensation， the eddy currents reduced to at least 1/15 of that before compensation. The diffusion-weighted EPI images with and without eddy currents compensation were compared. After two times of compensations， the geometric distortion was reduced by 5% and artifacts was reduced by 1/3. The experimental results showed that the proposed algorithm can effectively suppressed the diffusion-weighted EPI artifacts and distortions caused by eddy currents.

Key words: MRI(magnetic resonance imaging), EPI(echo-planar imaging), diffusion-weighted imaging, eddy currents, pre-emphasis

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