Magnetic resonance imaging in the evaluation of iron overload in patients with beta thalassaemia and sickle cell disease

Abstract

Magnetic resonance imaging (MRI) appears to be useful for monitoring iron overload in thalassaemia. We studied 106 patients with beta-thalassaemia: 80 with thalassaemia major (TM) and 26 with thalassaemia intermedia (TI). Thirty-five patients with sickle cell disease (SCD) were also evaluated. Serum ferritin, liver and myocardial T2-relaxation time and liver iron concentration (LIC) were measured. LIC values, based on biopsies from 29 patients, showed a close inverse correlation with the respective liver T2-values, along with a strong positive correlation with ferritin levels in all patients. Heart T2-values correlated with left ventricular ejection fraction in TM and SCD, but not in TI patients. Both liver and heart T2-values were significantly lower in TM patients than those of TI, and SCD patients. Ferritin levels showed a strong correlation with liver T2-values in all three groups of patients. Similarly, a negative correlation was found between serum ferritin levels and heart T2-values in TM, but not in TI and SCD patients. Heart and liver T2-values showed a significant correlation only in TM patients. These results suggest that the MRI technique (T2 relaxation time) used in our study, is a reliable, safe and non-invasive method for the assessment of the deposition of iron in the liver; results for the heart become reliable only when there is heavy iron deposition.