The usefulnes of Acoustic Radiation Force Impulse (ARFI) Elastography (ARFI) for evaluation of liver fibrosis - large monocentric experience

Purpose: To assess the value of liver stiffness (LS) measurements by means of ARFI as a predictive factor for the severity of fibrosis. Methods: Our study included 1150 subjects with an median age of 55 years (18 – 87): 652 patients (56.7%) diagnosed with liver cirrhosis by clinical, ultrasound, endoscopy criteria; 244 subjects (21.2%) without known liver disease, 133 patients (11.6%) with chronic hepatitis C in whom liver biopsy (LB) was performed, 72 chronic hepatitis B patients (6.3%) with LB and 49 patients (4.2%) with non-cirrhotic ascites. Ten LS valid ARFI measurements were performed in each subject and a median value was calculated, expressed in meters/second (m/s). Reliable LS measurements were considered the median of 10 valid measurements with a success rate≥60% and an interquartile range interval< 30%. Results: Reliable LS values by means of ARFI measurements were obtained in 1076/1150 (93.5%) subjects. In “normal subjects” the mean LS value assessed by ARFI was 1.22 ± 0.31 m/s (median 1.19 m/s) In patients with LB, the best LS ARFI cut-offs values for predicting different stages of liver fibrosis were: F≥2 – 1.48 m/s (AUROC = 0.671), F≥3 – 1.61 m/s (AUROC = 0.709) and F = 4 – 1.75 m/s (AUROC = 0.824). The mean LS values were significantly higher in cirrhotic patients with significant esophageal varices (al least grade 2) as compared with those without or with grade 1 varices: 2.96 ± 0.71 m/s vs. 2.81 ± 0.71 m/s, p = 0.01; also in cirrhotic with ascites as compared with those without ascites: 3.01 ± 0.70 m/s vs. 2.78 ± 0.68 m/s, p = 0.0001. The mean LS values assessed by ARFI were significantly higher in cirrhotic patients with ascites as compared with patients with non-cirrhotic etiology of ascites: 3.01 ± 0.70 m/s vs. 1.43 ± 0.49 m/s, p < 0.0001. Conclusion: ARFI is a good method for noninvasive liver fibrosis assessment.