Liver stiffness measurement using acoustic radiation force impulse (ARFI) elastography and effect of necroinflammation

Abstract

BACKGROUND: Acoustic radiation force impulse (ARFI) elastography can be used to assess the degree of liver fibrosis.

AIM: We evaluated the performance of ARFI elastography in assessment of liver fibrosis and compared it with the performance of aspartate aminotransferase-to-platelet ratio index (APRI) and transient elastography with Fibroscan (FS).

METHODS: We prospectively analyzed 250 consecutive patients who underwent liver biopsy and ARFI from June 2010 to May 2011. Reliable FS values were obtained for 97 (38.8%) patients.

RESULTS: The mean age of patients (147 male and 103 female) was 46.6 years. Liver stiffness values obtained by use of ARFI elastography significantly correlated with histological fibrosis stage (R = 0.575, P < 0.001). Area under the receiver operating characteristics curves (AUROCs) of ARFI elastography for predicting significant fibrosis (≥F2) and cirrhosis (F4) was 0.74 (95% confidence interval [CI], 0.64-0.86, P = 0.001) and 0.79 (95% CI, 0.67-0.91, P = 0.001), respectively, and those for APRI were 0.69 (95% CI, 0.58-0.79, P = 0.001) and 0.76 (95% CI, 0.64-0.85, P < 0.001), respectively. The optimum cutoff values for ARFI elastography were 1.13 m/s for ≥F2 and 1.98 m/s for F4; these decreased to 1.09 m/s for ≥F2 and 1.81 m/s for F4 when 131 patients with normal alanine aminotransferase (ALT) were selected. In the sub-group of 97 patients with reliable FS values, the performance in predicting ≥F2 or F4 was equivalent between ARFI elastography and FS.

CONCLUSIONS: ARFI elastography is a reliable surrogate marker of liver fibrosis, if its relationship with biochemical markers, for example ALT level, is taken into account.