Optimized Phase Schedules for Minimizing Peak RF Power in Simultaneous Multi-Slice RF Excitation Pulses

Eric Wong¹

Simultaneous excitation of multiple slices is proving useful for highly accelerated imaging. For N simultaneously excited slices, the peak RF power is increased by a factor of N² for excitation with uniform phase across slices. We demonstrate here that numerical optimization of the excitation phase across slices allows one to approach the theoretical minimum increase in peak power of a factor of N rather than N².