FIG 1. Single voxel PRESS proton MR spectra (TR/TE = 2000/135) demonstrate choline (Ch), creatine (Cr), and N-acetylaspartate (NAA) peaks from occipital gray matter (A), posterior white matter (B), thalamus (C), and pons (D). The axial T2 FSE image shows the voxel location for the acquired spectrum. The chemical shift scale is in parts per million relative to tetramethylsilane.