Localized proton MR spectroscopy of the normal human brain in vivo

The feasibility of localized water-suppressed photon spectroscopy of human brain in vivo was demonstrated on a conventional whole-body MR imaging system (Seimens Magneton). Localization was achieved with stimulated echo (STEAM) sequences. Typically, high-resolution proton MR imaging spectra (5-HZ line width) from a 27-mL (30 x 30 x 30 mm/sup 3/) VOI were obtained within measuring times of 1 - 10 minutes. Resonance assignments were made to lipids, lactate, acetate, γ-aminobutyrate, N-acetyl-aspartate, glutamine, glutamate, aspartate, creatine/phosphocreatine, choline compounds, glycine, and inositols. T1 and T2 relaxation times were determined that allowed estimates of metabolite concentrations relative to known values. For example, cerebral lactate was found to be less than 1.0 mM. Differences in relaxation times and concentrations of major metabolites were found in white and gray matter, thalamus, and cerebellum