Multi-echo functional MRS Glutamate measurements in visual cortex at 3T

fMRS studies have shown dynamic change in glutamate (Glu) concentrations during visual stimulation. Here, we examine the effect of TE from 9.3-280ms on the signal during fMRS acquisition and whether T2 relaxation parameters change during a visual task compared to rest. We observed a short Glu T2-compartment between 2.5-4.5ms arising from 48% (rest) and 16% (active) of the total signal with significant increase in Glu signal at TE =140ms during stimulation. These preliminary results indicate bi-exponential decay of Glu in the visual cortex at 3T encouraging future work with more robust fMRS paradigms.