Magnetic resonance imaging signal reduction may precede volume loss in the pituitary gland of transfusion-dependent beta-thalassemic patients

Abstract

Background: Pituitary iron overload in patients with transfusion-dependent beta-thalassemia may lead to delayed puberty. Magnetic resonance imaging (MRI) has the potential to estimate tissue iron concentration by detecting its paramagnetic effect and hypophyseal damage by measuring its dimensions indirectly. Purpose: To investigate the association of pituitary MRI findings and pubertal status in thalassemic patients as well as to demonstrate any priority in appearance of them. Material and Methods: Twenty-seven beta-thalassemic patients, aged 15–25 years, were divided into 13 with (group A) and 14 without hypogonadism (group B), matched by age, gender, duration of transfusion, and chelation therapy. Thirty-eight age- and sex-adjusted healthy control individuals were also included (group C). All participants underwent pituitary MRI using a 1.5T unit. Pituitary-to-fat signal intensity ratios (SIR) were calculated from coronal T2-weighted images. Estimated pituitary volumes were measured using pituitary height, width, and length on T1-weighted images. Results: The mean values of pituitary-to-fat SIRs were significantly lower in group A as compared with group B ( P <0.001), and likewise group B had statistically lower values than group C ( P=0.03). The pituitary height and volume were significantly decreased in group A compared to group B (P = 0.006 and P = 0.002, respectively), while these differences did not demonstrate statistically significance between groups B and C. Conclusion: Pituitary MRI findings such as signal intensity reduction and decrease in volume can be useful markers in estimating pituitary dysfunction in beta-thalassemic patients. Compared to healthy controls, lower values of pituitary-to-fat SIRs in thalassemic patients experiencing normal puberty, without marked decrease in volume, indicate that signal reduction may precede volume loss and could be expected first on MRI.