Resolution Improvements inin Vivo1H NMR Spectra with Increased Magnetic Field Strength

doi:10.1006/jmre.1998.1542

Journal of Magnetic Resonance

Volume 135, Issue 1, November 1998, Pages 260-264

https://doi.org/10.1006/jmre.1998.1542 Get rights and content

Abstract

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 γ-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 for¹H NMR, which can lead to more than linear sensitivity gains.

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Regular ArticleResolution Improvements inin Vivo1H NMR Spectra with Increased Magnetic Field Strength

Abstract

J. Magn. Reson. B

J. Magn. Reson. A

J. Magn. Reson.

J. Magn. Reson.

J. Magn. Reson. B

J. Magn. Reson.

J. Magn. Reson.

Proc. Natl. Acad. Sci. USA

J. Magn. Reson. Imaging

Magn. Reson. Med.

Magn. Reson. Med.

Magn. Reson. Med.

Magn. Reson. Med.

J. Magn. Reson.

Magn. Reson. Med

Magn. Reson. Med

Magn. Reson. Med.

Regular Article
Resolution Improvements inin Vivo¹H NMR Spectra with Increased Magnetic Field Strength