Quantitative T2* imaging of iron overload in a non-dedicated center - Normal variation, repeatability and reader variation.

ABSTRACT

BACKGROUND: Patients with transfusion dependent anemia are at risk of complications from iron overload. Quantitative T2* magnetic resonance imaging (MRI) is the best non-invasive method to assess iron deposition in the liver and heart and to guide chelation therapy. PURPOSE: To investigate the image quality and inter-observer variations in T2* measurements of the myocardium and the liver, and to obtain the lower limit of cardiac and hepatic quantitative T2* values in patients without suspicion of iron overload. MATERIAL AND METHODS: Thirty-eight patients referred for cardiac MRI were prospectively included in the study. Three patients were referred with, and 35 without suspicion of iron overload. Quantitative T2* parametric maps were obtained on a 1.5 T MRI system in the cardiac short axis and liver axial view. Two readers independently assessed the image quality and the representative and the lowest T2* value in the myocardium and the liver. RESULTS: The normal range of representative T2* values in the myocardium and liver was 24-45 ms and 14-37 ms, respectively. None of the 35 participants (0 %, 95 % confidence interval 0-11 %) in the normal reference group demonstrated representative T2* values below previously reported lower limits in the myocardium (20 ms) or the liver (8 ms). Focal myocardial areas with T2* values near the lower normal range, 19-20 ms, were seen in two patients. The readers generally reported good image quality. CONCLUSION: T2* imaging for assessing iron overload can be performed in a non-dedicated center with sufficient image quality.