Acoustic Radiation Force Impulse (ARFI) and Transient Elastography (TE) for evaluation of liver fibrosis in HIV-HCV co-infected patients (BMC Infectious Diseases)

Background: Transient elastography (TE) is widely used for non-invasive assessment of liver fibrosis in HIV-HCV co-infected patients. TE, however, cannot determine liver morphology. Acoustic radiation force impulse (ARFI) imaging is a novel procedure enabling assessment of liver fibrosis during a conventional ultrasonographic examination. This study evaluated the correlation between liver fibrosis measurements by TE and ARFI. Methods: Each of 46 HIV-HCV patients underwent both ARFI and TE within 6 months. Patients were evaluated by the `equivalent METAVIR` scoring system, using previously established cut-off values. Agreements between the ARFI and TE scores were estimated by Kappa coefficients, with Kappa values >=0.40, >=0.60, and >=0.80 defined as moderate, good and very good agreement, respectively. Results: ARFI and TE yielded `Equivalent Metavir` fibrosis scores of F1 in 26 and 31 patients, respectively; F2 in nine and seven, respectively; F3 in three and two, respectively; and F4 in eight and six, respectively. The two methods showed very good agreement in predicting overall stages [Kappa = 0.82] and for F >=3 [Kappa = 0.80] and moderate agreement in predicting significant fibrosis F >=2 [Kappa = 0.50]. Morphologic ultrasound analysis concomitant to ARFI detected two hepatocarcinomas. Conclusions: ARFI showed promising results in the non-invasive assessment of liver fibrosis in HIV-HCV patients, with liver fibrosis staging similar to that of TE. Moreover, ARFI can assess morphology and fibrosis during the same session.