Iron overload is a severe complication of multiple blood transfusions. As the body has no physiologic mechanism for clearing iron, repeated transfusions cause iron accumulation in organs and lead to iron toxicity. Accurate assessment of iron overload is paramount to quantify excessive iron accumulation and to monitor response to iron chelation therapy. Magnetic resonance imaging (MRI) methods have been used to noninvasively measure hepatic iron concentration (HIC). Although MRI-based measurements of transverse relaxation rates (R2 and R2*) accurately predict biopsy-proven HICs below 15 mg Fe/g, previous studies have shown that their precision is limited for HICs above 15 mg Fe/g and inaccurate above 25 mg Fe/g. Current R2* gradient-echo (GRE) MR techniques fail occasionally for very high iron overloads (HIC ~ 15-25 mg Fe/g) and always for massive iron overloads (HIC > 25 mg Fe/g) because R2* is so high that the MR signal decays before it can be measured accurately.