|B1(+)|-selective excitation pulse design using the Shinnar-Le Roux algorithm.

A new mathematical treatment and algorithm for the design of |B1(+)|-selective RF excitation pulses is presented and validated. The algorithm is based on a rotated Shinnar-Le Roux pulse design algorithm, wherein the pulse's frequency modulation waveform is directly designed by the algorithm, and its amplitude and sign modulation waveform takes the place of the gradient field. A new pulse configuration is described that enables excitation of large tip-angle slice-selective profiles. Experiments were performed to validate the pulses, and simulations were performed to characterize the pulses' sensitivity to off-resonance, and to compare them to adiabatic (BIR-4) pulses.