T2 relaxation rate as an index of pituitary iron overload in patients withbeta-thalassemia major

OBJECTIVE. In transfusion-dependent beta -thalassernia major, increased iro n deposition in the pituitary gland has a cytotoxic effect, leading mainly to hypogonadotropic hypogonadism. Early detection and quantification of iro n in the pituitary gland are of particular importance for successful treatm ent. The purpose of this study was to evaluate the T2 relaxation rate (1/T2 ) as a marker of pituitary siderosis. SUBJECTS AND METHODS. In 29 patients with beta -thalassemia major and 40 co ntrols, we assessed the 1/T2 of the pituitary gland in a 1.5-T MR unit, usi ng a multiecho spin-echo sequence. In all patients, an extensive endocrine evaluation was performed, including measurements of spontaneous and stimula ted levels of gonadotropins, thyroid hormones, growth hormone, insulinlike growth factor, and adrenal hormones. RESULTS. A positive correlation was found between the 1/T2 and the serum fe rritin level (r = 0.73, p < 0.001). The 1/T2 was higher in patients (mean, 0.020 msec(-1); SD, 0.006) compared with that of controls (mean, 0.011 msec (-1); SD. 0.001; p < 0.001). The 1/T2 was higher in patients with hypogonad otropic hypogonadism (mean, 0.024 msec(-1); SD, 0.006) in comparison with t hat of patients without any pituitary dysfunction (mean, 0.017 msec(-1); SD , 0.001; p < 0.05). CONCLUSION, The T2 relaxation rate could be used as an index of pituitary i ron overload, and it might be of value to monitor treatment with deferoxami ne in patients with <beta>-thalassemia major.