Figure 3. In vivo Z-spectra analysis at 15.2 T of the rat brain cortex (a), caudate putamen (b), and surrounding muscle (c) at various saturation powers (0.24 μT[green], 0.47 μT [blue], and 0.71 μT [turquoise]).

Z-spectra with error bars (i) shown with ROIs displayed in red in the anatomical image inset in each Z-spectrum. An enlarged view of the amide (blue arrow), PCr (orange arrow), and guanidyl peaks (brown arrow) are shown in [ii] for each Z-spectra.