1H metabolite relaxation times at 3.0 tesla: Measurements of T1 and T2 values in normal brain and determination of regional differences in transverse relaxation

J Magn Reson Imaging. 2004 May;19(5):537-45. doi: 10.1002/jmri.20053.


Purpose: To measure 1H relaxation times of cerebral metabolites at 3 T and to investigate regional variations within the brain.

Materials and methods: Investigations were performed on a 3.0-T clinical whole-body magnetic resonance (MR) system. T2 relaxation times of N-acetyl aspartate (NAA), total creatine (tCr), and choline compounds (Cho) were measured in six brain regions of 42 healthy subjects. T1 relaxation times of these metabolites and of myo-inositol (Ins) were determined in occipital white matter (WM), the frontal lobe, and the motor cortex of 10 subjects.

Results: T2 values of all metabolites were markedly reduced with respect to 1.5 T in all investigated regions. T2 of NAA was significantly (P < 0.001) shorter in the motor cortex (247 +/- 13 msec) than in occipital WM (301 +/- 18 msec). T2 of the tCr methyl resonance showed a corresponding yet less pronounced decrease (162 +/- 16 msec vs. 178 +/- 9 msec, P = 0.021). Even lower T2 values for all metabolites were measured in the basal ganglia. Metabolite T1 relaxation times at 3.0 T were not significantly different from the values at 1.5 T.

Conclusion: Transverse relaxation times of the investigated cerebral metabolites exhibit an inverse proportionality to magnetic field strength, and especially T2 of NAA shows distinct regional variations at 3 T. These can be attributed to differences in relative WM/gray matter (GM) contents and to local paramagnetism.

MeSH terms

  • Adult
  • Aspartic Acid / analogs & derivatives*
  • Aspartic Acid / metabolism
  • Brain / metabolism*
  • Choline / metabolism
  • Creatinine / metabolism
  • Female
  • Humans
  • Magnetic Resonance Spectroscopy*
  • Male
  • Protons


  • Protons
  • Aspartic Acid
  • N-acetylaspartate
  • Creatinine
  • Choline