Fig 2.
Proton MR spectroscopic image of water (H2O) at the level of the third ventricle obtained from a healthy control subject by means of the two-dimensional MR spectroscopic method described in Figure 1 without water suppression (A). The color scale denotes white as the highest and black as the lowest signal intensity. The superimposed pair of lines delineate the column of spectroscopic imaging voxels from which water spectra were obtained; these are displayed in a stacked plot in B. Clearly visible is a frequency shift and extensive broadening of the water resonance in the region of the head of the caudate nucleus, probably explaining the generally bad quality of caudate spectra (see Fig 1). The red line superimposed on the stacked plot of spectra corresponds to the frequency used for water suppression in metabolite proton MR spectroscopy.