Design of a 20-channel B0 shimming coil for human brain magnetic resonance imaging at 5T

Due to B0 field inhomogeneity caused by the variation of magnetic susceptibility distribution of tissue in human brain, image geometric distortion and signal dropout warping artifacts may be caused in functional magnetic resonance imaging (fMRI) studies, especially at ultra-high field magnetic resonance imaging (MRI). In this work, a 20-channel B0 shimming coil was designed and optimized on a 5T MRI scanner, of which shimming performance was comparable to that of a 40-channel shimming coil. While the optimized 20-channel shimming coil required half the number of power channels of the 40-channel shimming coil, which significantly reduced the hardware cost. The B0 field homogeneity across 8 human brains have been increased by 18.73% after using the proposed 20-channel B0 shimming coil. This will reduce image geometric distortion and signal loss, demonstrating great potential in brain function research.