Reduction of peak power using Time-Shifted Multiband pulses: (A) Pulse shapes, from left to right: conventional four-banded (MB4) pulse of duration t, composed of four single-banded (SB) sinc RF pulse (R = 5.2) with band #1 (no frequency offset) and band #4 ~3 kHz frequency offset; the same conventional MB4 pulse with stretched duration of 1.75·t, time-shifted MB4 pulse generated for duration 1.75·t (25% temporal shift between bands). For all plots, solid lines represent the magnitude, dashed lines the real component, and dotted lines the imaginary component. (B) Plot of required peak B1 vs. total pulse duration for four-banded pulses with 3 kHz inter-band frequency offsets: stretched conventional pulse (dark blue), time-shifted pulse (green), time-shifted with static (i.e. fixed) inter-band phase offsets (light blue), and time-shifted with optimized phase offsets for each shift (red). B1 and duration are shown relative to the base single-banded sinc pulse. Note that time shifted pulses ultimately achieve the same peak B1 whether or not phase optimization is employed. Adapted from ().