Quantitative glutamate spectroscopic imaging of the human hippocampus

NMR Biomed. 2006 Apr;19(2):209-16. doi: 10.1002/nbm.1019.

Abstract

We have evaluated a three-dimensional localized spectroscopic imaging sequence that uses two pairs of adiabatic full-passage pulses, which optimizes the detection of glutamate resonances at moderate echo times. This sequence provides excellent volume localization while simultaneously reducing J-modulation losses of glutamate. We have simulated the performance of this sequence for glutamate and used it to quantitatively measure glutamate in the human hippocampus using a linear components model. Using tissue segmentation and regression analysis, we measured a glutamate concentration of 8.8 +/- 2.1 mM in hippocampal and temporal gray matter and 3.7 +/- 1.1 mM in temporal white matter (95% CI). We have used this approach in a small group of patients (n = 5) with unilateral hippocampal epilepsy.

Publication types

  • Controlled Clinical Trial

MeSH terms

  • Adult
  • Algorithms
  • Epilepsy / diagnosis*
  • Epilepsy / metabolism*
  • Female
  • Glutamic Acid / analysis
  • Glutamic Acid / metabolism*
  • Hippocampus / anatomy & histology*
  • Hippocampus / metabolism*
  • Humans
  • Image Interpretation, Computer-Assisted / methods
  • Magnetic Resonance Imaging / methods*
  • Magnetic Resonance Spectroscopy / methods*
  • Male
  • Neurotransmitter Agents / analysis
  • Neurotransmitter Agents / metabolism
  • Tissue Distribution

Substances

  • Neurotransmitter Agents
  • Glutamic Acid