Fig 6. Sensitivity analysis for varying relaxation rates.

(a) All measured relaxation rates $R_2^{\left(i\right)}$ for the 3.5h experimental data (Fig 5a) were varied within different ranges $\delta R_2^{\left(i\right)}$ with $\forall i\text{:}\delta R_2^{\left(i\right)}/R_2^{\left(i\right)}=\text{const}$. For multiple sets of such variations, the average of the resulting difference to and in proportion of the initially obtained radius R _A is negligible for relative ranges < 0.01. (b) Scatter plot of the resulting radii vs. deviations for the example $R_2^{\left(10\right)}=R_2({\tau }_{180}=17\text{ms})$ for different strengths of variation; all other $R_2^{\left(i\right)}$ values were also varied within their respective error ranges as in (a).