Acoustic Radiation Force Impulse Elastography for fibrosis evaluation in patients with chronic hepatitis C: An international multicenter study

Aim: The aim of this international multicenter study was to evaluate the reliability of Acoustic Radiation Force Impulse (ARFI) elastography for predicting fibrosis severity, in patients with chronic hepatitis C. Patients and methods: We compared ARFI to liver biopsy (LB) in 914 patients (10 centers, 5 countries) with chronic hepatitis C. In each patient LB (evaluated according to the METAVIR score) and ARFI measurements were performed (median of 5-10 valid measurements, expressed in meters/second - m/s). In 400 from the 914 patients, transient elastography (TE) was also performed (median of 6-10 valid measurements, expressed in kiloPascals - kPa). Results: Valid ARFI measurements were obtained in 911 (99.6%) of 914 cases. On LB 61 cases (6.7%) had F0, 241 (26.4%) had F1, 202 (22.1%) had F2, 187 (20.4%) had F3, and 223 (24.4%) had F4 fibrosis. A highly significant correlation (r = 0.654) was found between ARFI measurements and fibrosis (p < 0.0001). The predictive values of ARFI for various stages of fibrosis were: F ≥ 1 - cut-off > 1.19 m/s (AUROC = 0.779), F ≥ 2 - cut-off > 1.33 m/s (AUROC = 0.792), F ≥ 3 - cut-off > 1.43 m/s (AUROC = 0.829), F = 4 - cut-off > 1.55 m/s (AUROC = 0.842). The correlation with histological fibrosis was not significantly different for TE in comparison with ARFI elastography: r = 0.728 vs. 0.689, p = 0.28. TE was better than ARFI for predicting the presence of liver cirrhosis (p = 0.01) and fibrosis (F ≥ 1, METAVIR) (p = 0.01). Conclusion: ARFI elastography is a reliable method for predicting fibrosis severity in chronic hepatitis C patients.