Risk of abnormal OGTT as a function of MRI risk. MRI risk was considered low if both the heart and pancreas had no significant iron overload. Isolated pancreas iron loading (R2* >100 Hz) represented medium risk. Cardiac iron loading (T2* <20 ms) represents high risk; no patient had isolated cardiac iron loading. OGTT results were graded according to American Diabetes Association Standards and were coded as normal (NML), impaired fasting glucose (IFG), impaired glucose tolerance (IGT), and diabetes mellitus (DM). The prevalence and severity of glucose abnormalities increased with MRI risk. (Figure redrawn with permission from Noetzli et al.³⁹ )