Spectrally-Selective Refocusing for Brain Glutamate and Glutamine Measures: Application to Human Prefrontal and Motor Cortices
Choi C, Coupland N, Kalra S, Malykhin N, Bhardwaj P, Gheorghiu D, Allen P
University of Alberta
A new proton NMR single-voxel filtering strategy for selective measurement of glutamate (Glu) and glutamine (Gln) in human brain is proposed. Spectrally-selective refocusing by long (> 80 ms) 180&[deg] RF pulses, at 3.0 T, was explored for discrimination of the Glu and Gln C4-proton multiplets in separate scans. The refocusing frequencies and echo times, optimized both numerically and experimentally, rendered measurements of Glu and Gln with negligible contamination from N-acetylaspartate and glutathione. Preliminary in vivo results from human prefrontal and motor cortices are reported.