Quantitative MRI in the evaluation of patients with non-alcoholic steatohepatitis (NASH)

To evaluate the reliability of quantitative magnetic resonance imaging (MRI) in the diagnosis and follow-up of patients with NASH. Methods or Background From March to September 2021 twenty patients who met diagnostic criteria for NASH and twenty healthy volunteers were enrolled and underwent quantitative 1.5T MRI examination of the liver. Acquisition protocol comprised magnetic resonance elastography (MRE) and proton density fat fraction (PDFF). Image post-processing was performed with a dedicated workstation. Quantitative image analysis was performed by a radiologist with 15 years of experience in abdominal MRI; liver stiffness (kPa) and grade of steatosis (%) were collected. Statistical analysis was performed using a dedicated software and a p value <0.05 was considered significant. Results or Findings Liver stiffness was higher in patients with NASH than in healthy volunteers (10.8±6.42 kPa vs 4.75±1.44 kPa; p=0.0002). PDFF was higher in patients with NASH than in healthy volunteers (2.52±0.56% vs 1.87±0.26%; p=0.0020). Steatosis was present in 100% of patients in the NASH group (15% in healthy volunteers); NASH group showed elevated liver stiffness in 80% of patients (0% in healthy volunteers). Quantitative MRI performance for liver stiffness and PDFF detection showed an area under the curve (AUC) of 0.915 (sensitivity 100%; specificity 75%) and 0.843 (sensitivity 60%; specificity 90%), respectively. The whole time examination was 72 seconds (55 seconds for MRE and 17 seconds for PDFF). Conclusion Quantitative MRI techniques are reliable in the study of NASH. Furthermore, being very fast and risk-free protocols, these technique could also be used as a screening method in populations at risk of developing diffuse liver disease. Limitations The small population sample and lack of multivariate clinical-radiological analysis were identified limitations.