Quantitative glutamate spectroscopic imaging of the human hippocampus.
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.
Magnetic Resonance Research Center and Department of Neurology, Albert Einstein College of Medicine, Bronx, New York 10461, USA. jpan@aecom.yu.edu
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Venkatraman
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Vives
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D000328:Adult; D000465:Algorithms; D004827:Epilepsy / Q000175:diagnosis* / Q000378:metabolism*; D005260:Female; D018698:Glutamic Acid / Q000032:analysis / Q000378:metabolism*; D006624:Hippocampus / Q000033:anatomy & histology* / Q000378:metabolism*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D018377:Neurotransmitter Agents / Q000032:analysis / Q000378:metabolism; D014018:Tissue Distribution
D018377:Neurotransmitter Agents; D018698:Glutamic Acid