Free-breathing Imaging Techniques for Liver Iron Quantification: Comparison with a Validated Breath-hold Technique in Patients with Iron Overload

Introduction: Hepatic iron content (HIC) measurements utilizing quantitative T2* maps have become an increasingly used alternative to traditional HIC evaluation obtained by liver biopsy. The advantages of T2* based HIC measurements are the non-invasive nature of the precedure and a relatively short measurement time. Recently several studies were presented, that correlated biopsy based HIC measurements with T2* measurements. These studies showed excellent agreement between biopsy and MRI [1,2]. The validation was, however, only performed for a multi-gradient echo sequence obtained in a single breathhold. With this technique it is not always possible to consistently acquire artifact-free T2* maps, especially in a population of young, sedated, or uncooperative patients. Another study reports a free-breathing approach for iron quantification, but this work was not validated with data from liver biopsies [3]. Therefore, the aim of this study is to implement and compare different free-breathing T2* based HIC techniques with a validated breath-hold method in patients with liver iron overload.