Localized high-resolution proton NMR spectroscopy using stimulated echoes: initial applications to human brain in vivo.
Water-suppressed localized proton NMR spectroscopy using stimulated echoes has been successfully applied to detect metabolites in the human brain in vivo. The STEAM spectroscopy sequence allows single-step localization by exciting three intersecting slices. Water suppression is achieved by preceding chemical-shift-selective (CHESS) rf pulses. High-resolution (0.05 ppm) proton NMR spectra of healthy volunteers have been High-resolution (0.05 ppm) proton NMR spectra of healthy volunteers have been obtained on a conventional 1.5-T whole-body MRI system (Siemens Magnetom). Volumes-of-interest (VOI) of 64 ml (4 x 4 x 4 cm3) were localized in the occipital area of the brain and spectra were recorded within measuring times ranging from 1 s (single scan) to about 10 min. The experimental procedure is described in detail. Resonance assignments include acetate, N-acetyl aspartate, gamma-amino butyrate, glutamine, glutamate, aspartate, creatine and phosphocreatine, choline-containing compounds, taurine, and inositols. Cerebral lactate was found to be at a maximum concentration of 0.5 mM when assuming N-acetyl aspartate in white matter to be 6 mM.
Frahm
J
J
Max-Planck-Institut für biophysikalische Chemie, Göttingen, Federal Republic of Germany.
Bruhn
H
H
Gyngell
M L
ML
Merboldt
K D
KD
Hänicke
W
W
Sauter
R
R
D000227:Adenine Nucleotides / Q000378:metabolism; D000596:Amino Acids / Q000378:metabolism; D001921:Brain / Q000378:metabolism*; D006801:Humans; D007773:Lactates / Q000378:metabolism; D050356:Lipid Metabolism; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy / Q000295:instrumentation / Q000379:methods; D008280:Magnetics; D011522:Protons; D014867:Water
D000227:Adenine Nucleotides; D000596:Amino Acids; D007773:Lactates; D011522:Protons; D014867:Water