Figure 1.

Representative MRS voxel selection for two subjects at different echo times. Left panel represents axial T1-weighted post-contrast images in the radiological orientation for a subject with true progression (A) and PsP (D). The box surrounding the representative voxels and enhancing lesion represents the MRS volume of interest, the boxes overlaid on the enhancing lesion represent the voxels from which the average Cho, Lac, Glx, and mI metabolite ratios were averaged, and the boxes overlaid on the contralateral hemisphere represent the voxels which were used to quantify the contralateral creatine which served as denominator for average Cho/c-Cr, mI/c-Cr, Lac/c-Cr, and Glx/c-Cr. The middle panel illustrates short echo time (TE) spectra obtained from a single voxel within the enhancing region for a patient with disease progression (B) and PsP (E). The right panel illustrates intermediate TE spectra obtained from a single voxel within the enhancing region for a patient with disease progression (C) and PsP (F). Lac, lactate; NAA, N-acetylasparate; Cho, choline; Cr, creatine; mI, myo-Inositol; Glx, glutamate/glutamine.