中国物理B ›› 2018, Vol. 27 ›› Issue (5): 58702-058702.doi: 10.1088/1674-1056/27/5/058702

• INTERDISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY • 上一篇    下一篇

Equivalent magnetic dipole method used to design gradient coil for unilateral magnetic resonance imaging

Zheng Xu(徐征), Xiang Li(李想), Pan Guo(郭盼), Jia-Min Wu(吴嘉敏)   

  1. 1 State Key Laboratory of Power Transmission Equipment & System Security and New Technology, Chongqing University, Chongqing 400044, China;
    2 School of Physics and Electronic Engineering, Chongqing Normal University, Chongqing 401331, China
  • 收稿日期:2017-12-15 修回日期:2018-02-01 出版日期:2018-05-05 发布日期:2018-05-05
  • 通讯作者: Zheng Xu, Pan Guo E-mail:xuzheng@cqu.edu.cn;guopan@cqnu.edu.cn
  • 基金资助:

    Project supported by the National Natural Science Foundation of China (Grant Nos.51677008,51377182,51707028,and 11647098),the Fundamental Research Funds of the Central Universities,China (Grant No.106112017CDJQJ158834),and the State Key Development Program for Basic Research of China (Grant No.2014CB541602).

Equivalent magnetic dipole method used to design gradient coil for unilateral magnetic resonance imaging

Zheng Xu(徐征)1, Xiang Li(李想)1, Pan Guo(郭盼)2, Jia-Min Wu(吴嘉敏)1   

  1. 1 State Key Laboratory of Power Transmission Equipment & System Security and New Technology, Chongqing University, Chongqing 400044, China;
    2 School of Physics and Electronic Engineering, Chongqing Normal University, Chongqing 401331, China
  • Received:2017-12-15 Revised:2018-02-01 Online:2018-05-05 Published:2018-05-05
  • Contact: Zheng Xu, Pan Guo E-mail:xuzheng@cqu.edu.cn;guopan@cqnu.edu.cn
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Grant Nos.51677008,51377182,51707028,and 11647098),the Fundamental Research Funds of the Central Universities,China (Grant No.106112017CDJQJ158834),and the State Key Development Program for Basic Research of China (Grant No.2014CB541602).

摘要:

The conventional magnetic resonance imaging (MRI) equipment cannot measure large volume samples nondestructively in the engineering site for its heavy weight and closed structure. In order to realize the mobile MRI, this study focuses on the design of gradient coil of unilateral magnet. The unilateral MRI system is used to image the local area above the magnet. The current density distribution of the gradient coil cannot be used as a series of superconducting nuclear magnetic resonance gradient coils, because the region of interest (ROI) and the wiring area of the unilateral magnet are both cylindrical side arc surfaces. Therefore, the equivalent magnetic dipole method is used to design the gradient coil, and the algorithm is improved for the special case of the wiring area and the ROI, so the X and Y gradient coils are designed. Finally, a flexible printed circuit board (PCB) is used to fabricate the gradient coil, and the magnetic field distribution of the ROI is measured by a Gauss meter, and the measured results match with the simulation results. The gradient linearities of x and y coils are 2.82% and 3.56%, respectively, less than 5% of the commercial gradient coil requirement.

关键词: unilateral MRI, equivalent magnetic dipole method, gradient coil, current density distribution

Abstract:

The conventional magnetic resonance imaging (MRI) equipment cannot measure large volume samples nondestructively in the engineering site for its heavy weight and closed structure. In order to realize the mobile MRI, this study focuses on the design of gradient coil of unilateral magnet. The unilateral MRI system is used to image the local area above the magnet. The current density distribution of the gradient coil cannot be used as a series of superconducting nuclear magnetic resonance gradient coils, because the region of interest (ROI) and the wiring area of the unilateral magnet are both cylindrical side arc surfaces. Therefore, the equivalent magnetic dipole method is used to design the gradient coil, and the algorithm is improved for the special case of the wiring area and the ROI, so the X and Y gradient coils are designed. Finally, a flexible printed circuit board (PCB) is used to fabricate the gradient coil, and the magnetic field distribution of the ROI is measured by a Gauss meter, and the measured results match with the simulation results. The gradient linearities of x and y coils are 2.82% and 3.56%, respectively, less than 5% of the commercial gradient coil requirement.

Key words: unilateral MRI, equivalent magnetic dipole method, gradient coil, current density distribution

中图分类号:  (Magnetic resonance imaging)

  • 87.61.-c
84.32.Hh (Inductors and coils; wiring) 02.30.Zz (Inverse problems)