Chemical shifts of anticonvulsants and metabolites
Spectrum of the healthy human brain with main metabolites ranging between 0 and 4 ppm. The localization of the voxel of interest (VOI) for the volume selective spectroscopy is depicted in three orthogonal slice projections (upper part of figure). Metabolites are assigned as follows: Ins (inositol), Cho (choline), Cr (creatine), Naa (N -acetylaspartate). The region between 4 ppm to about 6 ppm is overlapped by incompletely suppressed water signals and therefore not suited for reliable analysis. The chemical shift range for the aromatic protons of the anticonvulsants carbamazepine, phenobarbital, and phenytoin as well as for the aliphatic protons of valproate are marked by transparent bars.