Jason P Stockmann1, Bastien Guerin1,2, and Lawrence L Wald1,2
1A. A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States, 2Harvard Medical School, Boston, MA, United States
Integrated RF-shim coils combine RF receive arrays
and matrix shim arrays into a single set of close-fitting loops, provide a
promising alternative to spherical harmonic shim coils for compensating dynamic
high-order B0 offsets in the brain. However, the potentially large design
space for optimizing these arrays remains little explored. In this work,
we investigate ways to improve the efficiency of RF-shim coils by (a.) creating
“hybrid” RF-shim arrays that use additional shim-only loops over the face for targeted shimming of the frontal lobes and (b.) using a genetic algorithm to choose optimal
subarrays of coils for shimming, thus reducing hardware complexity.