Assessment of liver fibrosis with acoustic radiation force impulse imaging versus liver histology in patients with chronic hepatitis C: a pilot study.

BACKGROUND: Acoustic radiation force impulse imaging (ARFI) involves the mechanical excitation of tissues using short-duration acoustic pulses to generate localized displacements in tissue. The displacements results in shear-wave propagation, tracked by ultrasonography (US) correlation-based methods and recorded in meters per seconds.

AIM: To compare (ARFI) integrated into a conventional US with the standard histological examination of liver biopsy specimens for the assessment of liver fibrosis.

MATERIALS AND METHODS: Histological fibrosis staging with standard liver biopsy using the Metavir scoring system as well as fibrosis assessment using ARFI were performed to 80 patients with chronic hepatitis C over a 3-month period.

RESULTS: ARFI findings were identical to the biopsy findings in 61 (76.25%) patients.Fifty-eight (67.5%) patients with an early fibrosis stage (F0, F1, and F2) by histology had identical fibrosis stages using ARFI.Only 20 out of 26 patients with an advanced fibrosis stage (F3 and F4) using ARFI had advanced fibrosis histologically. In the advanced fibrosis stages, the sensitivity of ARFI was 70% and specificity was 80%, with positive and negative predictive values of 53.8 and 88.9%, respectively. The accuracy of detection of advanced fibrosis by ARFI was 77.5%.

CONCLUSION: ARFI imaging is a promising noninvasive US-based method for the assessment of liver fibrosis.