R2* Mapping of Extreme Hepatic Iron Overload Using Free-Breathing UTE Sequence

Motivation: Existing liver iron quantification methods are inadequate for extreme iron deposition, hindering effective guidance for iron chelation therapy. Goal(s): Evaluate the practicality of a free-breathing, single-echo UTE sequence with varying echo times for multiple acquisitions in assessing severe hepatic iron overload. Approach: A 3.0T UTE sequence with rigid-based motion correction was used to assess hepatic R2* in nine thalassemia patients, and compared with LIC from Ferriscan and R2* from a 1.5T GRE sequence. Results: UTE-R2* correlated well with GRE-R2* and Ferriscan-LIC, and could differ hepatic iron content in patients whose Ferriscan-LIC or GRE-R2* reach to upper limit. Impact: An imaging strategy utilizing a free-breathing, single-echo UTE sequence with variable echo times for multiple acquisitions, combined with rigid-based motion correction, could be employed to evaluate extreme hepatic iron deposition.