The orthogonal shim coil for 3T brain imaging

Tutkimustuotos: Lehtiartikkelivertaisarvioitu


  • Jiazheng Zhou
  • Jason P. Stockmann
  • Nicolas Arango
  • Thomas Witzel
  • Klaus Scheffler
  • Lawrence L. Wald
  • Fa-Hsuan Lin


  • Univ Tubingen, Eberhard Karls University of Tubingen, Grad Training Ctr Neurosci, IMPRS
  • Harvard Med Sch, Harvard University, Harvard Medical School
  • Massachusetts Institute of Technology
  • Univ Hosp Tubingen UKT, Eberhard Karls University of Tubingen, EBERHARD KARLS UNIVERSITY HOSPITAL, Biomed Magnet Resonance
  • Univ Toronto, University of Toronto, Dept Med Biophys
  • Sunnybrook Res Inst, University of Toronto, Sunnybrook Health Science Center, Sunnybrook Research Institute, Phys Sci Platform


Purpose: We designed and implemented an orthogonal shim array consisting of shim coils with their planes perpendicular to the planes of neighboring RF coils. This shim coil improves the magnetic field homogeneity by minimizing the interference to RF coils. Methods: Using realistic off-resonance maps of the human brain, we first evaluated the performance of shim coils in different orientations. Based on simulations, we developed a 7-channel orthogonal shim array, whose coil plan was perpendicular to neighboring RF coils, at the forehead. A programmable open-source current driver supplied shim currents. Results: The 7-channel orthogonal shim array caused only marginal SNR loss to the integrated 32-channel RF-shim array. The 7-channel orthogonal shim array itself improved the magnetic field homogeneity by 30% in slice-optimized shimming, comparable to the baseline shimming offered by the scanner's 2nd order spherical harmonic shimming. Conclusion: Orthogonal shim coils can improve the field homogeneity while maintaining high image SNR.


JulkaisuMagnetic Resonance in Medicine
TilaJulkaistu - 21 lokakuuta 2019
OKM-julkaisutyyppiA1 Julkaistu artikkeli, soviteltu

ID: 38445471