Combined Quantitative Fat and Stiffness Phantom for Simultaneous CSE-MRI and MRE Quality Assurance of Steatotic Liver Disease

Motivation: A quantitative fat/stiffness phantom would facilitate quality assurance of chemical shift encoded (CSE) MRI and MR elastography (MRE) data. Goal(s): Develop a quantitative fat/stiffness phantom that simultaneously mimics clinically-relevant levels of proton density fat fraction (PDFF) and stiffness. Approach: Formulated PDFF-stiffness gels were poured into a housing with stackable cylindrical compartments and an integrated passive MRE driver. PDFF and stiffness were measured in each compartment and stiffness was externally validated with mechanical testing. Results: A phantom was fabricated with target PDFF/stiffness values of 0%/1.5kPa, 10%/3kPa, and 20%/4kPa. MRE stiffness values correlated well with external mechanical testing (r2 = 0.95). Impact: A quantitative three-compartment fat/stiffness phantom was developed and optimized to address the need for standardized quality assurance of quantitative MRI biomarkers of steatotic liver disease.