In vivo 1H NMR spectroscopy of the human brain at 7 T.
In vivo 1H NMR spectra from the human brain were measured at 7 T. Ultrashort echo-time STEAM was used to minimize J-modulation and signal attenuation caused by the shorter T2 of metabolites. Precise adjustment of higher-order shims, which was achieved with FASTMAP, was crucial to benefit from this high magnetic field. Sensitivity improvements were evident from single-shot spectra and from the direct detection of glucose at 5.23 ppm in 8-ml volumes. The linewidth of the creatine methyl resonance was at best 9 Hz. In spite of the increased linewidth of singlet resonances at 7 T, the ability to resolve overlapping multiplets of J-coupled spin systems, such as glutamine and glutamate, was substantially increased. Characteristic spectral patterns of metabolites, e.g., myo-inositol and taurine, were discernible in the in vivo spectra, which facilitated an unambiguous signal assignment.
Tkác
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Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, Minnesota 55455, USA. ivan@cmrr.umn.edu
Andersen
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Adriany
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Merkle
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H
Ugurbil
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K
Gruetter
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R
D000328:Adult; D001921:Brain / Q000033:anatomy & histology / Q000502:physiology*; D001931:Brain Mapping; D004734:Energy Metabolism / Q000502:physiology*; D006801:Humans; D007089:Image Enhancement; D009682:Magnetic Resonance Spectroscopy; D018377:Neurotransmitter Agents / Q000378:metabolism*; D012016:Reference Values
D018377:Neurotransmitter Agents