Investigating metabolite regional dependencies in the frontal lobe: overlapping small and large voxels

Small anatomically specific voxels in cerebral cortex require a large number of averages to quantify metabolites by magnetic resonance spectroscopy. It is unclear whether cortical regional variability in metabolite concentration requires small voxels, or whether a larger voxel which incorporates the region of interest can provide adequately representative measures with fewer averages. Concentrations of glutamate, glx, creatine, choline, myo­-inositol and N-acetyl-aspartate (NAA) were correlated within subjects between an overlapping small (15x15x15mm) and large (30x30x30mm) voxel. There was a significant correlation between creatine measures, while choline showed a positive trend. There was no correlation between glutamate, glx, NAA, and myo-inositol.