Functional diffusion-weighted magnetic resonance spectroscopy of the human primary visual cortex at 7 T

Magn Reson Med. 2013 Feb;69(2):303-9. doi: 10.1002/mrm.24542. Epub 2012 Nov 19.


Purpose: Microstructural and metabolic changes directly related to neuronal activation have been investigated using functional diffusion-weighted spectroscopy.

Methods: The volume of interest was positioned in the primary visual cortex. A time series of alternating diffusion- and non-diffusion-weighted (1)H spectra was acquired at 7 T employing stimulated echo acquisition mode sequence and a long diffusion time (Δ = 245 ms). Time-resolved series of metabolite apparent diffusion coefficient values were derived.

Results: Significant increases in apparent diffusion coefficient of 3.3 ± 1.4% (p = 0.05) and 3.9 ± 0.9% (p = 0.002) for total n-acetyl aspartate and total creatine, respectively, and 8.1 ± 2.5% (p = 0.03) for total choline were observed in response to visual stimulation.

Conclusion: The increase in apparent diffusion coefficient for these metabolites is a potential indication for microstructural changes in neurons during neural activation and/or for an increase in the energy-dependent cytoplasmic streaming associated with enhanced metabolism during visual stimulation.

MeSH terms

  • Adult
  • Aspartic Acid / analogs & derivatives*
  • Aspartic Acid / metabolism
  • Choline / metabolism*
  • Creatine / metabolism*
  • Diffusion Magnetic Resonance Imaging / methods*
  • Evoked Potentials, Visual / physiology
  • Female
  • Humans
  • Magnetic Resonance Spectroscopy / methods*
  • Male
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Visual Cortex / physiology*
  • Visual Perception / physiology*


  • Aspartic Acid
  • N-acetylaspartate
  • Creatine
  • Choline