Low peak power multiband spokes pulses for B-1( ) inhomogeneity-compensated simultaneous multislice excitation in high field MRI

Abstract

PURPOSE: To design low peak and integrated power simultaneous multislice excitation radiofrequency pulses with transmit field inhomogeneity compensation in high field MRI. THEORY AND METHODS: The "interleaved greedy and local optimization" algorithm for small-tip-angle spokes pulses is extended to design multiband (MB) spokes pulses that simultaneously excite multiple slices, with independent spokes weight optimization for each slice. The peak power of the pulses is controlled using a slice phase optimization technique. Simulations were performed at 7T to compare the peak power of optimized MB spokes pulses to unoptimized pulses, and to compare the proposed slice-independent spokes weight op..