T(2) relaxation rate of basal ganglia and cortex in patients with beta-thalassaemia major.

摘要

In thalassaemic patients, neurophysiological disturbances have been associated with high serum ferritin levels and desferrioxamine therapy. In the presence of a magnetic field, ferritin, the main iron storage protein, induces a preferential decrease of the T(2) relaxation time. The purpose of this study was to evaluate thalassaemic patients for brain iron deposition by assessing the T(2) relaxation rate (1/T(2)) of the grey matter. 41 thalassaemic patients (age range 8.5-44 years, mean 24 years) and 58 age- and sex-matched controls were included in the study. Current serum ferritin levels were obtained. The 1/T(2) values of the cortex (motor and temporal) (mean 0.0122 ms(-1), SD 0.0004), putamen (mean 0.0137 ms(-1), SD 0.0004) and caudate nucleus (mean 0.0132 ms(-1), SD 0.0003) were higher in patients compared with the controls (mean 0.0110 ms(-1), SD 0.0004; mean 0.0120 ms(-1), SD 0.0005; mean 0.0117 ms(-1), SD 0.0003, respectively) (p<0.001 for all parameters). No statistically significant differences were found in the globus pallidus. No correlation was found between 1/T(2) and serum ferritin. The higher values of 1/T(2) in the cortex, putamen and caudate nucleus of thalassaemic patients probably reflect a higher iron deposition. The lack of differences in 1/T(2) of the globus pallidus might suggest that even in thalassaemic patients iron cannot exceed a saturation level.