Fast Optimal Control Method for Large-tip-angle RF Pulse Design in Parallel Excitation

Introduction The optimal control method [1,2] is among existing techniques for large-tip-angle RF pulse design in parallel excitation [1,3-5]. Optimal control has some advantages over other methods; it is robust, it applies to general excitation trajectories, and it provides control over the excited phase pattern. However, it requires long computation times, rendering it unsuitable for online pulse design. We introduce a fast optimal control method that achieves the same accuracy as optimal control in a shorter time, and with reduced memory requirements.