Figure 2. B1 dispersion experiments.
a) Z-spectra are plotted as a function of saturation frequency offset (∆ω, in units of ppm) from water resonance (∆ω = 0 ppm) for varying nominal B1 amplitudes (1 μT to 3 μT) acquired in the arm muscle of a healthy female volunteer. b-c) Z-values in the range of APT and NOE are plotted as a function of B1 amplitude, and fit to a second order polynomial (red line). Error bars represent one standard deviation of the parameter within the axillary ROI.