The effects of the analysis technique on hepatic iron evaluation using T2∗ mapping with magnetic resonance imaging

Iron toxicity is the major factor for tissue damage and organ failure in patients with iron overload. T2* measurement with magnetic resonance imaging (MRI) has been established as an effective and non-invasive technique for evaluating iron content in the liver. However, different factors related to the adopted image processing criterion affect the resulting measurements. These factors include the exponential fitting model (single exponential, bi-exponential, or exponential + constant) and the size and location of the selected region of interest and whether it includes vasculature, susceptibility artifacts, or is close to the liver boundary. In this study, we investigate the effects of these various factors on T2* measurement using calibrated phantoms with different amounts of iron as well as on patients with different degrees of iron overload. The results show various degrees of similarities and differences between different processing techniques, which should be known by the operator for better selection of the image processing parameters and proper interpretation of the resulting measurements.