Resolution improvements in in vivo 1H NMR spectra with increased magnetic field strength

J Magn Reson. 1998 Nov;135(1):260-4. doi: 10.1006/jmre.1998.1542.


The measurement of cerebral metabolites using highly homologous localization techniques and similar shimming methods was performed in the human brain at 1.5 and 4 T as well as in the dog and rat brain at 9.4 T. In rat brain, improved resolution was achieved by shimming all first- and second-order shim coils using a fully adiabatic FASTMAP sequence. The spectra showed a clear improvement in spectral resolution for all metabolite resonances with increased field strength. Changes in cerebral glutamine content were clearly observed at 4 T compared to 1.5 T in patients with hepatic encephalopathy. At 9.4 T, glutamine H4 at 2.46 ppm was fully resolved from glutamate H4 at 2.37 ppm, as was the potential resonance from gamma-amino-butyric acid at 2.30 ppm and N-acetyl-aspartyl-glutamate at 2.05 ppm. Singlet linewidths were found to be as low as 6 Hz (0.015 ppm) at 9.4 T, indicating a substantial decrease in ppm linewidth with field strength. Furthermore, the methylene peak of creatine was partially resolved from phosphocreatine, indicating a close to 1:1 relationship in gray matter. We conclude that increasing the magnetic field strength increases spectral resolution also for 1H NMR, which can lead to more than linear sensitivity gains.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Amino Acids / analysis
  • Animals
  • Brain Chemistry*
  • Dogs
  • Hepatic Encephalopathy / metabolism
  • Humans
  • Image Processing, Computer-Assisted
  • Inositol / analysis
  • Lactic Acid / analysis
  • Magnetic Resonance Spectroscopy*
  • Protons
  • Rats
  • Reproducibility of Results
  • Stereoisomerism


  • Amino Acids
  • Protons
  • scyllitol
  • Lactic Acid
  • Inositol