MRI for the determination of pituitary iron overload in children and young adults with β-thalassaemia major

Hypogonadism, resulting from iron-induced pituitary dysfunction, is the most frequently reported complication in patients with beta-thalassaemia major. The aim of this study was to evaluate pituitary Magnetic Resonance Imaging (MRI) signal intensity reduction, on T2*-weighted images, as a marker of pituitary iron overload. Thirty patients (13 females and 17 males, mean age: 16.6 +/- 4.1) with beta-thalassaemia major on conventional treatment and 13 healthy volunteers (7 females and 6 males, mean age: 11 +/- 4.51 years) were studied with T2*-weighted images of the anterior pituitary using a 1.5 T unit. Four thalassaemic patients (2 females and 2 males) had clinical hypogonadism and required hormonal replacement treatment. Results revealed a statistically significant reduction of pituitary signal intensity in the thalassaemia group compared to controls (p < 0.001). Moreover, hypogonadal patients had significantly decreased MRI values compared to thalassaemic patients without hypogonadism (P=0.017). Relatively decreased adeno-hypophyseal MRI signal intensity was recorded in pubertal thalassaemic patients. A significant negative correlation was observed between pituitary MRI values and age (r = -0.67, r(2) = 0.443, p = 0.001), whereas ferritin levels and pituitary MRI values were moderately correlated (r = -0.56, r(2) = 0.32, p = 0.08) in adult thalassaemic patients. In conclusion, pituitary MRI indices as measured on T2*-weighted images seem to reflect pituitary iron overload and could, therefore, be used for a preclinical detection of patients who are in greater danger of developing hypogonadism. (c) 2006 Elsevier Ireland Ltd. All rights reserved.