永磁磁共振扩散加权平面回波成像涡流伪影校正  

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

作　　者：王艳飞[1] 杨金柱[2,3] 康雁 WANG Yan-fei;YANG Jin-zhu;KANG Yan(College of Medicine and Biomedical Information Engineering,Northeastern University,Shenyang 110169,China;Key Laboratory of Intelligent Computing in Medical Image,Ministry of Education,Northeastern University,Shenyang 110169,China;School of Computer Science&Engineering,Northeastern University,Shenyang 110169,China;College of Health Science and Environmental Engineering,Shenzhen Technology University,Shenzhen 518118,China)

机构地区：[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

出　　处：《东北大学学报（自然科学版）》2020年第7期1048-1053,共6页Journal of Northeastern University(Natural Science)

基　　金：国家自然科学基金青年基金资助项目(61602101).

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. 35 T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.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 0.35 T 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.

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 

分 类 号：TP197.39[自动化与计算机技术—控制理论与控制工程]