Gradient swept adiabatic pulses for out of slice inversion and outer volume suppression.

Motivation: Slice selective adiabatic pre-pulses have many uses in magnetic resonance. Using gradient waveforms to create adiabatic rotations creates new ways to prepare magnetization. Goal(s): Explore adiabatic pulse with frequency sweeps created by gradient wave forms instead of RF frequency waveforms. Approach: Gradient swept adiabatic inversion pulses were tested with numerical Bloch simulations and on a phantom in a 3T scanner. Results: The pulses can invert magnetization outside a well-defined non-perturbed slice. Sub-adiabatic use allows outer volume suppression, and the non-perturbed slice can be transformed into a wedge with additional constant orthogonal gradients. Impact: A new class of adiabatic inversion pulses with frequency sweeps generated by gradient waveforms to yield inversion outside a well-defined non-perturbed slice or wedge delivers new options for pre-pulses for contrasts, spatial selection, or outer volume suppression.