The Effect of Strong Homonuclear Proton Coupling on a PRESS-Localized ge-HMQC Sequence
Yahya A, Allen P
University of Alberta
This work demonstrates that when 13C-coupled protons of a metabolite are simultaneously involved in strong coupling with neighboring protons the outcome to a basic gradient-enhanced Heteronuclear Multiple Quantum Coherence (ge-HMQC) sequence differs from the expected outcome, namely, a 50% yield for 13C-coupled protons, and zero signal for 12C-bonded protons. The effects are exacerbated when the sequence is combined with PRESS to enable 3D localization. Glutamate at 3.0 T was used as an illustrative example, and numerical calculations were confirmed on a 99% 13C3 enriched glutamate phantom.