Macromolecule-suppressed GABA acquisition at 7T with commonly available Gaussian editing pulses.

Co-editing of macromolecule(MM) resonances is a major problem in J-difference based editing (e.g. MEGA-PRESS) at 3T and lower field strengths. Symmetrical pulsing centered at the 1.7 ppm MM resonance alleviates this problem but results in loss of desired GABA signal, in addition to loss of unwanted MM signal, due to high bandwidth of frequency-selective editing pulses. Larger separation of editing pulses at 7T reduces the problem, but large chemical shift displacement errors, especially at low B1, make MEGA-PRESS non-viable at 7T. Using a low-power MEGA-LASER sequence, we measured macromolecule minimized GABA at 7T with editing pulses having bandwidths available in most scanners.