Titre
Resolution improvements in in vivo 1H NMR spectra with increased magnetic field strength.
Type
article
Institution
Externe
Périodique
Auteur(s)
Gruetter, R.
Auteure/Auteur
Weisdorf, S.A.
Auteure/Auteur
Rajanayagan, V.
Auteure/Auteur
Terpstra, M.
Auteure/Auteur
Merkle, H.
Auteure/Auteur
Truwit, C.L.
Auteure/Auteur
Garwood, M.
Auteure/Auteur
Nyberg, S.L.
Auteure/Auteur
Uğurbil, K.
Auteure/Auteur
Liens vers les personnes
ISSN
1090-7807
Statut éditorial
Publié
Date de publication
1998
Volume
135
Numéro
1
Première page
260
Dernière page/numéro d’article
264
Langue
anglais
Notes
Publication types: Comparative Study ; Journal Article ; Research Support, Non-U.S. Gov't ; Research Support, U.S. Gov't, P.H.S.Publication Status: ppublish
Résumé
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.
PID Serval
serval:BIB_246B15679972
PMID
Date de création
2010-08-04T14:28:27.109Z
Date de création dans IRIS
2025-05-20T19:15:00Z