Sebastian Schmitter1, Xiaoping Wu1, Lance DelaBarre1, Kamil Ugurbil1, Pierre-Francois Van de Moortele1
1Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States
B1 shimming achieves high transmit B1 (B1+) efficiency with satisfactory B1+ homogeneity in small targets at 7T, however in large targets, e.g. heart, uniform |B1+| with static B1 shim results in low efficiency. Taking advantage of typical |B1+| profiles observed with transceiver arrays in the heart at 7T, we propose a new concept where, instead of aiming at homogeneous |B1+| profile, B1 shim is applied to achieve a predefined spatially distorted |B1+| pattern which, in turn, allows for efficient use of 1D spoke RF pulse design to provide homogeneous excitation in the heart while preserving high B1+ efficiency.