Magnetic resonance elastography for staging liver fibrosis in non-alcoholic fatty liver disease: a diagnostic accuracy systematic review and individual participant data pooled analysis

Objectives: We conducted an individual participant data (IPD) pooled analysis on diagnostic accuracy of MRE to detect fibrosis stage in patients with non-alcoholic fatty liver disease (NAFLD). Methods: Through a systematic literature search, we identified studies of MRE (at 60–62.5 Hz) for staging fibrosis in patients with NAFLD, using liver biopsy as gold standard, and contacted study authors for IPD. Through pooled analysis, we calculated the cluster-adjusted AUROC, sensitivity and specificity of MRE for any (≥stage 1), significant (≥stage 2) and advanced (≥stage 3) fibrosis and cirrhosis (stage 4). Results: We included nine studies with 232 patients with NAFLD (mean age, 51 ± 13 years; 37.5 % males; mean BMI, 33.5 ± 6.7 kg/m²; interval between MRE and biopsy <1 year, 98.3 %). Fibrosis stage distribution (stage 0/1/2/3/4) was 33.6, 32.3, 10.8, 12.9 and 10.4 %, respectively. Mean AUROC (and 95 % CIs) for diagnosis of any, significant or advanced fibrosis and cirrhosis was 0.86 (0.82–0.90), 0.87 (0.82–0.93), 0.90 (0.84–0.94) and 0.91 (0.76–0.95), respectively. Similar diagnostic performance was observed in stratified analysis based on sex, obesity and degree of inflammation. Conclusions: MRE has high diagnostic accuracy for detection of fibrosis in NAFLD, independent of BMI and degree of inflammation. Key points: • MRE has high diagnostic accuracy for detection of fibrosis in NAFLD. • BMI does not significantly affect accuracy of MRE in NAFLD. • Inflammation had no significant influence on MRE performance in NAFLD for fibrosis.