MRI-based evaluation of the factors leading to pituitary iron overload in patients with thalassemia major

Given the lack of studies evaluating pituitary iron overload in patients with thalassemia major, we used magnetic resonance imaging (MRI) to evaluate these patients and the factors affecting the disease process. The 84 patients with β-thalassemia major who were included in this study were referred to our clinic for cardiac and hepatic T2* MRI. T2*-weighted images of the pituitary gland, heart, and liver were obtained using a 1.5-tesla MRI unit and a multi-echo gradient-echo sequence. Associations between pituitary T2*, cardiac T2*, hepatic T2*, pituitary height, serum ferritin (SF) level, patient age, and other demographic findings were assessed. Pituitary T2* values correlated with hepatic T2* values, cardiac T2* values, SF level, and patient age (P ≤ 0.001, 0.001, 0.001, 0.01, respectively) but not with pituitary height (P = 0.76). Pituitary and cardiac T2* values were lower in the subset of patients who underwent splenectomy (P = 0.046 and P = 0.002, respectively). Pituitary iron overload rapidly increases during puberty and in this study correlated with cardiac and hepatic T2* values, patient age, SF level, and liver size, but not with the height of the pituitary. Pituitary iron overload also increases following splenectomy. Together, these findings indicate that numerous factors contribute to pituitary iron overload.