Self-Refocused Adiabatic Pulse for Spin Echo Imaging at 7T

Priti Balchandani¹, John Pauly², Daniel Spielman¹

Adiabatic 180 pulses may be used to replace conventional 180 pulses in spin echo sequences to provide greater immunity to the inhomogeneous B₁-field at 7T. However, because the spectral profile of an adiabatic 180 pulse has non-linear phase, pairs of these pulses are used for refocusing, resulting in increased SAR and longer minimum echo times. We have used the adiabatic SLR method to generate a matched-phase 90 for an adiabatic 180 pulse to obviate the need for a second 180 pulse. The pulse pair was combined into a single self-refocused pulse to achieve the minimum echo time, and phantom and in vivo experiments were performed to validate pulse performance.