Clinical Analysis of Magnetic Resonance Imaging T2* Tests on Iron Overload in Children With β-Thalassemia Major

Abstract

Objective To investigate the clinical significance of magnetic resonance imaging T2-star (MRI T2*) tests on iron overload in children with β-thalassemia major. Methods Nineteen children with β-thalassemia major were recruited in this study during January to December 2010. Retrospective analytical study on the history of blood transfusion and chelation therapy were recorded. Sera were obtained from the patients and were tested for serum ferritin. MRI T2* tests on iron overload of liver, heart, pancreas and pituitary in these children were performed in Queen Mary Hospital, Hong Kong. The results were evaluated, and the relationships between different values of iron overload were analyzed. The study protocol was approved by the Ethical Review Board of Investigation in Human Being of Sun Yat-sen Memorial Hospital, Sun Yat-sen University. Informed consent was obtained from the parents of each participating child. Results All the patients received irregular blood transfusion and chelation therapy. The value of serum ferritin ranged from 3114 μg/L to 14 550 μg/L. The organs of the patients showed different degrees of iron overload by MRI T2* detection. Levels of serum ferritin were negatively correlated with liver MRI T2*, left ventricular ejection fraction, and pancreas MRI T2* (r=-0.569, P= 0.011; r=—0.633, P= 0.004;r=- 0.592, P= 0.008). In addition, there were positive correlation between heart MRI T2* and pancreas MRI T2* (r=0.696, P= 0.001), between pancreas MRI T2* and pituitary MRI T2* (r=0.491, P= 0.033) as well. Conclusion MRI T2* tests show clinical significance for evaluating iron overload in children with β-thalassemia major. Key words: thalassemia; iron overload; serum ferritin; magnetic resonance imaging