Spectroscopic imaging of human brain glutamate by water-suppressed J-refocused coherence transfer at 4.1 T

The authors report the development and implementation of a water-suppressed J-refocused coherence transfer sequence to observe glutamate in human brain at 4.1 T, The sequence is modeled for I2S2 and I(2)S(2)M spin systems analytically and plotted for a range of echo times. In this sequence, water suppression and refocusing of J-coupled resonances are achieved through a brief multiple quantum step without significant loss of signal, Phantom data are shown, Human brain spectroscopic imaging of glutamate, acquired with a total echo of 36 ms, demonstrates the application of the sequence to observe gray and white matter differences in glutamate content.