Magnetic resonance imaging-derived measures of liver fat and volume are emerging as accurate, non-invasive imaging biomarkers in non-alcoholic steatohepatitis (NASH).
Little is known about these measures in relation to histology longitudinally.
Professor Loomba and colleagues from California, USA examined any relationship between MRI-derived proton-density fat-fraction, total liver volume, total liver fat index, vs. histology in a NASH trial.
The researchers performed a secondary analysis of a 24-week randomized, double-blind, placebo-controlled trial of 50 patients with biopsy-proven NASH randomized to oral ezetimibe 10 mg daily vs. placebo.
Baseline and post-treatment anthropometrics, biochemical profiling, MRI and biopsies were obtained.
The research team found that baseline mean proton-density fat-fraction correlated strongly with total liver fat index, and had good correlation with total liver volume.
Mean total liver volume correlated strongly with total liver fat index.
|Total liver volume remained strongly correlated with total liver fat index|
|Alimentary Pharmacology & Therapeutics|
After 24 weeks, the team noted that proton-density fat-fraction remained strongly correlated with total liver fat index, maintaining good correlation with total liver volume.
The research found that total liver volume remained strongly correlated with total liver fat index.
Patients with Grade 1 vs. 3 steatosis had lower proton-density fat-fraction, total liver volume, and total liver fat index.
The research compared changes in MRI-proton-density fat-fraction vs. total liver volume, which indicated that 10% reduction in MRI-proton-density fat-fraction predicts 257 mL reduction in total liver volume.
Professor Loomba's team comments, "The MRI-proton-density fat-fraction and total liver volume strongly correlated with total liver fat index."
"Decreases in steatosis were associated with an improvement in hepatomegaly."
"Lower values of these measures reflect lower histologic steatosis grades."
"MRI-derived measures of liver fat and volume may be used as dynamic, and more responsive imaging biomarkers in a NASH trial, than histology."