A novel fast algorithm for parallel excitation: pulse design in MRI.

Spatially selective excitations with parallel transmitters have been regarded as a key in solving several high field MRI problems such as inhomogeneity correction and reducing specific absorption rate. However, three-dimensional pulse design in general is very time consuming which may prevent it from real-time applications. In this work, we explore the sparsity in the pulse design system equation. The size of system equation is reduced after a sparse transform and therefore design speed can be significantly increased. Computer simulations in several common scenarios show that the proposed design method can achieve up to an order of magnitude speedup than the conventional design methods while maintaining similar excitation accuracy.