Figure 5.

GABA and Lys 3.01 ppm resonances when MEGA-PRESS editing is simulated with the symmetric pulsing scheme (editing pulses at 1.9 and 1.52 ppm, blue) for elimination of MM contribution relative to the base scheme (editing pulses at 1.9 and 7.46 ppm, black). For symmetric pulsing, instead of setting the “off” pulse of the editing symmetric about water, they were set symmetric about the problematic coupling partner. Since Lys was used to imitate MM, the symmetric pulse was placed at 1.52 ppm, i.e., symmetric about the 1.71 ppm chemical shift of Lys ⁵CH₂ relative to the 1.9 ppm used for GABA editing.