Mapping cardiac |B1+| field with B1+ prepared imaging

Cardiac MRI at 3T offers gains in SNR, but is strongly affected by field inhomogeneities, including the transmit field B1+. Mapping |B1+| field around the heart is particularly challenging due to the presence of motion, and few techniques exist for robust imaging. Recently, Bloch-Siegert shift mapping was proposed for motion robust cardiac |B1+| mapping, however, it requires long echo times making it more susceptible to artifacts. Here, we introduce a new preparation module for efficient |B1+| mapping. The method shows 0.06% / 0.35% reduced noise variability in phantom and 0.61±0.35% / 0.89±0.63% in-vivo imaging, and visually improved map quality.