Increased myocardial extracellular volume fraction and native T1 in sickle cell anemia. Scatterplots showing increased (A) ECV and (B) native T1 in SCA compared with normal controls. Dotted lines represent the reported lower and upper normal limits. (C) Bar graph demonstrating the mean ECV values in previously published studies of fibrotic heart diseases (shown in green),^21-27  in comparison with normal controls (shown in blue) and SCA patients in this study (shown in red). Dashed line represents the upper limit of normal. CMP, cardiomyopathy; MI, myocardial infarction; TM, thalassemia major (+iron, indicates presence of myocardial iron overload).