Figure 7.

Experimental relationship between ${\varsigma }_{B_1^{+}}$ and ${\varsigma }_{{\epsilon }_r}$. Both ${\varsigma }_{B_1^{+}}$ and ${\varsigma }_{{\epsilon }_r}$ were evaluated in 2 manually delineated ROIs matching the phantom inner and outer compartments. For ${\varsigma }_{B_1^{+}}$, the average value is displayed. The horizontal bars indicate the spread (std) of the ${\varsigma }_{B_1^{+}}$ in both ROIs. The black line represents the theoretical model29 relating ${\varsigma }_{{\epsilon }_r}$ and ${\varsigma }_{B_1^{+}}$ for the noise‐robust kernel K_vL (Equation 18 in Lee et al,29 where N_tot= 117, L =√67, G = 290.2, and ${\varsigma }_{B_1^{+}\approx }$ ≈ 1/$SN{R}_{B_1^{+}}$). The black asterisks refer to the std values of the permittivity calculated by Lee et al29 inside 3 ROIs, for a simulated phantom $B_1^{+}$ map with fictitious $SN{R}_{B_1^{+}}$ = 300