The evaluation of renal iron deposition with a 3 Tesla MRI device in beta-thalassemia major patients

Abstract

Background and objective Beta-thalassemia is the most frequent monogenic disease in the world. In beta-thalassemia major (BTM) patients, blood transfusions for severe anemia usually cause iron overload, leading to increased morbidity and mortality. In this study, we aimed to examine the iron overload in the kidneys of BTM patients with a 3 Tesla (3T) MRI device and assess the relationship between iron overload in the liver and heart as well as serum ferritin levels. Methods This was a retrospective study covering the period between November 2014 and March 2015. MRI was performed on 21 patients with BTM who were receiving blood transfusions and chelation therapy. The control group (n=11) included healthy volunteers. A 3T MRI device (Ingenia, Philips, Best, The Netherlands) using a 16-channel phased array SENSE-compatible torso coil was used. Three-point DIXON (mDIXON) sequence and the relaxometry method were employed to measure iron overload. Both kidneys were analyzed via mDIXON sequence for atrophy or variations. Afterward, the images in which renal parenchyma could be distinguished best were selected. Iron deposition was analyzed via the relaxometry method using a unique software (CMR Tools, London, UK). All data were analyzed using IBM SPSS Statistics v.21 (IBM Corp., Armonk, NY). The Kolmogorov-Smirnov test, independent samples t-test, Mann-Whitney U test, and Pearson's and Spearman's rho correlation coefficient were used. A p-value <0.05 was considered statistically significant. Results There was a statistically significant relationship between beta-thalassemia patients who had cardiac iron deposition and those who did not in terms of T2* time (p=0.02). In contrast, there was no similar relationship for liver iron deposition (p>0.05). Renal T2* values were significantly different between the patient and control groups (p=0.029). T2* times were significantly different between patients who had ferritin levels below 2500 ng/ml and those with ferritin levels above 2500 ng/ml (p=0.042). Conclusion Based on our findings, 3T MRI is a safe and reliable tool for screening iron overload in BTM patients as it makes distinguishing between renal parenchyma and renal sinus much easier and as it is more sensitive to iron deposition.