BACKGROUND: Growth failure and pubertal delay are earliest sequelae of iron toxicity in thalassemia due to iron deposition in pituitary gland. This study evaluated pituitary volume and iron overload by 3T MRI in beta thalassemia.

METHODS: 57 patients with beta thalassemia and 30 controls were evaluated by 3T MRI pituitary R2 and T2*. Cardiac, hepatic and pancreatic iron overload were assessed by MRI T2*. Anterior pituitary volume evaluated by MRI planimetry. Mean serum ferritin estimated by sandwich immuno-assay. Short stature was defined as height <3^rd percentile for age. Clinical hypogonadism was defined as absence of secondary sexual characteristics in females ≥13 and males ≥14 years.

RESULTS: 32(56.1%) patients had short stature. 11(23.4%) of 47 pubertal patients had hypogonadism. Serum ferritin correlated positively with pituitary R2 (p = 0.0004) and negatively with anterior pituitary volume (p = 0.006). Pituitary R2 correlated negatively with cardiac T2* (p = 0.001). Patients with hypogonadism had lower pituitary T2* (p = 0.048) and anterior pituitary volumes (p = 0.012) as compared to those with normal sexual maturity. No significant differences were observed between pituitary R2 (p = 0.267) and T2* (p = 0.451) in patients with short stature as compared to those without. Mean pituitary R2 in patients was higher than in controls (p= 0.0001). Anterior pituitary volume was lower in patients than controls (p= 0.0001).

CONCLUSION: MRI is a reliable method to detect pituitary iron overload and predict risk of hypogonadism in β Thalassemia.