Evaluation of Low-Field MRI for R2* and Fat Fraction Quantification in the Concomitant Presence of Hepatic Iron Overload and Steatosis

Motivation: For coexisting hepatic iron overload and steatosis, MRI signal decay increases with field strength, complicating simultaneous R2* and fat fraction (FF) estimation at higher field strengths. Goal(s): To assess R2* and FF estimation accuracy at 0.55T compared to 1.5T using virtual hepatic iron overload and steatosis models and iron-fat phantoms. Approach: Creating virtual liver models simulating in vivo hepatic iron overload and steatosis morphology and iron-fat phantoms with varying iron contents and FF, and estimating R2* and FF across different SNRs. Results: 0.55T shows promising results for concurrent R2* and FF estimation, improving accuracy and precision compared to 1.5T, especially with enhanced SNR. Impact: Low-field 0.55T MRI is a viable approach to improve the measurable range of R2* and FF estimation compared to 1.5T in coexisting conditions of hepatic iron overload and steatosis.