Reproducibility of brain spectroscopy at 7T using conventional localization and spectral editing techniques

J Magn Reson Imaging. 2013 Aug;38(2):460-7. doi: 10.1002/jmri.23997. Epub 2013 Jan 4.


Purpose: To evaluate the reproducibility of spectroscopic measurements from the anterior cingulate (AC) and the dorsolateral prefrontal cortex (DLPFC) regions at 7T using a 32-channel head coil.

Materials and methods: Spectra were acquired in four healthy subjects each scanned twice using a stimulated echo acquisition mode (STEAM) sequence, and a MEGA-PRESS-IVS sequence for gamma-aminobutyric acid (GABA) editing. STEAM spectra were quantified using LCModel, whereas MEGA-PRESS-IVS data were analyzed using peak integrals determined using in-house software. Mean coefficient of variation (CV) and mean absolute difference between visits were calculated.

Results: For the AC STEAM dataset, the mean CV between visits was 6.2% for prominent metabolites such as N-acetylaspartate (NAA), total creatine (tCr), and total choline (tCho) and 6.3% for low signal-to-noise ratio (SNR) metabolites such as glutamate (Glu), glutamine (Gln), and GABA. The mean CV between visits for the DLPFC STEAM dataset was 8.5% for prominent metabolites and 21% for lower SNR metabolites. In the AC, the reproducibility measures for GABA were superior for STEAM compared to MEGA-PRESS-IVS (mean CV of 3.5% vs. 13.6%), but the opposite pattern was observed in the DLPFC region (mean CV of 16.2% vs. 13.4%).

Conclusion: 7T MR spectroscopy of the AC and DLPFC using both short TE STEAM and MEGA-PRESS-IVS sequences provide excellent reproducibility of 12 metabolites, including GABA.

Keywords: 7T; GABA; STEAM; magnetic resonance spectroscopy; reproducibility.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Aspartic Acid / analogs & derivatives*
  • Aspartic Acid / metabolism
  • Brain / anatomy & histology
  • Brain / metabolism*
  • Choline / metabolism*
  • Creatinine / metabolism*
  • Female
  • Healthy Volunteers
  • Humans
  • Image Interpretation, Computer-Assisted / methods*
  • Magnetic Resonance Imaging / methods*
  • Magnetic Resonance Spectroscopy / methods*
  • Male
  • Molecular Imaging / methods
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Tissue Distribution
  • Young Adult


  • Aspartic Acid
  • N-acetylaspartate
  • Creatinine
  • Choline