GABA-edited 7T spectroscopy using semi-adiabatic spatial-spectral pulses (GABA-SASSI) improves sensitivity, SAR and water suppression

Motivation: To leverage the additional sensitivity and spectral selectivity offered by ultrahigh field spectroscopy, an B1-insensitive adiabatic spectral editing sequence developed for the detection of GABA. Goal(s): GABA SASSI offers comparable performance to MEGA PRESS with lower SAR deposition and therefore faster TR, lower chemical shift artifact and foolproof water suppression. Approach: The GABA SASSI sequence implemented pulses developed by the adiabatic SLR algorithm with 95% ON bandwidth of 400 Hz (1.35 ppm) and transition bands of just 50 Hz (0.17ppm) Results: GABA SASSI successfully resolved the characteristic 3.0 ppm peak of GABA in the editing experiment, both in phantom and in vivo. Impact: This pilot project demonstrates the implementation and performance of the GABA SASSI sequence for spectral editing with B1 insensitivity at 7T. The GABA SASSI sequence offers faster performance and inherently superior water suppression compared to MEGA PRESS.