Preferential patterns of myocardial iron overload by multislice multiecho T*2 CMR in thalassemia major patients

Abstract

T*(2) multislice multiecho cardiac MR allows quantification of the segmental distribution of myocardial iron overload. This study aimed to determine if there were preferential patterns of myocardial iron overload in thalassemia major. Five hundred twenty-three thalassemia major patients underwent cardiac MR. Three short-axis views of the left ventricle were acquired and analyzed using a 16-segment standardized model. The T*(2) value on each segment was calculated, as well as the global value. Four main circumferential regions (anterior, septal, inferior, and lateral) were defined. Significant segmental variability was found in the 229 patients with significant myocardial iron overload (global T*(2) <26 ms), subsequently divided into two groups: severe (global T*(2) <10 ms) and mild to moderate (global T*(2) between 10 and 26 ms) myocardial iron overload. A preferential pattern of iron store in anterior and inferior regions was detected in both groups. This pattern was preserved among the slices. The pattern could not be explained by additive susceptibility artifacts, negligible in heavily iron-loaded patients. A significantly higher T*(2) value in the basal slice was found in patients with severe iron overload. In conclusion, a segmental T*(2) cardiac MR approach could identify early iron deposit, useful for tailoring chelation therapy and preventing myocardial dysfunction in the clinical setting.