Hanno Homann1, Kay Nehrke2, Ingmar Graesslin2, Olaf Dssel1, Peter Brnert2
Parallel transmission allows compensating for RF transmit field inhomogeneities and simultaneous SAR reduction by RF shimming. This study demonstrates that the trade-off between these two objectives can be overcome by using several different, adapted RF pulses: When sampling the center of the k-space, a highly uniform but relatively SAR-intensive excitation is performed to achieve optimal contrast. In the outer k-space, the homogeneity requirement is relaxed to reduce the average SAR. The concept is discussed theoretically; proof-of-principle is given based on phantom and in vivo images.