Magnetic Resonance Elastography for Liver Fibrosis Assessment

MRE was performed using either MRE hardware (GE Healthcare, Waukesha, WI, USA) with a 1.5-T imaging system or a 1.5-T whole-body magnetic resonance unit (Gyroscan Intera, Philips Medical Systems, Best, the Netherlands) with a four-element torso coil. The two-dimensional MRE protocols used were similar to those described in the literature [17 (link),18 (link)]. Liver stiffness (LS) values were calculated as the median values in multiple regions of interest on elastograms. The cutoff values for significant and advanced hepatic fibrosis were based on the MRE standards for LS of 2.91–3.59 kPa and ≥3.60 kPa, respectively [19 (link),20 (link)]. The NAFLD fibrosis score (NFS) was calculated using the following formula: –1.675 + 0.037 × age (years) + 0.094 × BMI (kg/m²) + 1.13 × impaired fasting glucose/diabetes (yes = 1, no = 0) + 0.99 × AST (aspartate aminotransferase)/ALT (alanine aminotransferase) ratio– 0.013 × platelet count (× 10⁹/L)– 0.66 × albumin (g/dL). The Fibrosis-4 Index (FIB-4) was calculated using the following formula: age × AST (IU/L) / platelet count (10⁹/L) × √ALT (IU/L) [21 (link)].