Quantification of Undecoupled 13C NMR Spectra in the Brain
Deelchand D, Henry P, Ugurbil K
University of Minnesota
Proton-decoupling has restricted the implementation of 13C NMR spectroscopy for human studies at ultra-high fields, mainly due to power deposition. We show that incorporation of 13C label into brain amino acids can be monitored accurately using localized 13C spectroscopy without 1H-decoupling in rat brain at 9.4T. Quantification was performed using LCModel with prior knowledge of J-coupling constants. Although the Cramer-Rao Bounds observed in undecoupled spectra were higher than decoupled spectra, the degradation was less than the peak S/N loss while both metabolites time courses were in excellent agreement. The study suggests the possibility of performing 13C human studies at fields>4T.