Fig. 4.

B1⁺ map (in percent of the nominal flip angle) of single subject (same as in Fig. 3) estimated by UNICORT (B1_UNICORT; left column) and measured with the 3D EPI technique (B1_m; center column). Percent differences in B1⁺ values between B1_UNICORT and B1_m (B1_UNICORT − B1_m; right column). At the edge of the brain, in the connective tissue and muscles the measured B1⁺ maps are less accurate and cause edge artifacts.