Rapid and simplified post-processing for B0 and B1 mapping with WASABI-RADISH in the application of CEST at 7T

Motivation: WASABI provides high fidelity B0 and B1 maps necessary for CEST correction yet suffers from prolonged post-processing incompatible with clinical use. Goal(s): Our goal was to design an optimisation-free method to expedite map estimations. Approach: A direct relationship was derived between B0 and B1 and information in WASABI Z-spectra. Results: The proposed approach accelerated post-processing by a factor of 80, with improved estimation in brain regions that are noisy and/or have unpredictable initial magnetisation. Impact: Improvement in speed and accuracy provided by RADISH has the ability to make WASABI, and quantitative CEST at ultra-high-field in general, more reliable and clinically feasible.