Measuring Glutamate in the Human Brain by MRS: Reproducibility using Time Domain fitting at 3 Tesla.
Davies K, Leitao E, Singh S, Mistry S, Jefferson S, Williams S, Hamdy S
University of Manchester
Measurement of glutamate by MRS is difficult because of overlap with other signals, notably glutamine. However, at 3T the spectra of glutamate and glutamine do not completely overlap, and separation of the resonances is feasible. Here we report results from a reproducibility study in which serial glutamate measurements were made in 3 brain areas in 5 normal volunteers in a 3T magnet. Time domain fitting was performed using prior knowledge derived from phantom measurements and simulations. The within-subjects coefficient of variation for glutamate in each brain region was between 9-13%, similar to NAA (7-11%).