Motivation: Effective head imaging at ultra-high field requires optimized RF management. A universal B1+ shim solution could allow efficient RF transmission and enable calibration-free imaging at 10.5T. Goal(s): To calculate the universal B1+ shim solution and evaluate its feasibility in brain structural imaging. Approach: Generated a universal B1+ shim from 22 B1+ field measurements, then compared it with subject-specific shims using T1-weighted structural imaging at 10.5T. Results: No significant quantitative differences were found between universal and subject-specific shims. Images acquired with each method exhibited strengths and weaknesses, but the universal RF shim improves user experience by eliminating the need for separate calibration. Impact: Simpler and faster acquisition of head structural images at 10.5T using a universal RF shim.
Park et al. (Tue,) studied this question.