A new adiabatic inversion pulse.

Abstract

Adiabatic pulses play an important role in magnetization inversion in the presence of RF field inhomogeneity. In this work the authors present an efficient adiabatic inversion pulse that is able to selectively invert magnetization over a large frequency bandwidth in a short time. The pulse is constructed in two steps: (i) the optimal trajectory is determined and (ii) the optimal rate of motion along that trajectory is determined. The resulting pulse enables separately controlling and trading off the pulse duration against the transition width. The superiority of this pulse over the well known sech/tanh adiabatic pulse is demonstrated in a scenario where a large bandwidth should be inverted at a short time using limited B1 amplitude.