Decreases in cT1 and liver fat content reflect treatment-induced histological improvements in MASH

MRI biomarkers of liver disease are robust and reproducible alternatives to liver biopsy. Emerging data suggest that absolute reduction in iron-corrected T1 (cT1) of ≥80 ms and relative reduction in liver fat content of 30% reflect histological improvement. We aimed to validate the associations of changes to these non-invasive biomarkers with histological improvement, specifically the resolution of steatohepatitis. We performed a retrospective analysis of participants from three interventional clinical trials who underwent multiparametric MRI to measure liver cT1 and liver fat content (LFC) (LiverMultiScan) alongside biopsies at baseline and end of study. Responders were defined as those achieving resolution of steatohepatitis with no worsening in fibrosis. Differences in the magnitude of change in cT1 and LFC between responders and non-responders were assessed. Individual patient data from 150 participants were included. There was a significant decrease in liver cT1 (-119 ms vs. -49 ms) and LFC (-65% vs. -29%) in responders compared to non-responders (p