Journal of Northeastern University Natural Science ›› 2020, Vol. 41 ›› Issue (7): 1048-1053.DOI: 10.12068/j.issn.1005-3026.2020.07.021

• Biologic Engineering • Previous Articles     Next Articles

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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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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