Assessment of hepatic fibrosis by analysis of the dynamic behaviour of microbubbles during contrast ultrasonography

Abstract

Background/aims: Microbubble behaviour from the portal vein to the liver parenchyma may reflect haemodynamic changes because of hepatic fibrosis. The aim of this study was to determine the efficacy of contrast-enhanced ultrasound (US) with Sonazoid™ for the assessment of the grade of hepatic fibrosis.

Methods: This prospective study evaluated 117 patients with chronic liver disease (chronic hepatitis 85; cirrhosis 32) and 34 controls. All subjects received both contrast-enhanced US with Sonazoid™ for 1 min after the agent injection and subsequent liver biopsy. Flow velocity and flow volume in the right portal vein, onset time of contrast enhancement in the right hepatic artery and right portal vein, maximum intensity ratio between the intra-hepatic portal vein and liver parenchyma, and time interval between the onset time and the time of maximum intensity ratio were compared with the pathological findings.

Results: Among the evaluated parameters, time interval between the onset time and the time of maximum intensity ratio showed the closest relationship with the grade of hepatic fibrosis: 4.21 ± 1.32 for controls (n=34), 5.58 ± 1.39 for F1 (n=31), 6.79 ± 1.77 for F2 (n=28), 8.85 ± 1.97 for F3 (n=26) and 14.3 ± 3.49 for cirrhosis (n=32); controls vs. F2, P=0.0004; F1 vs. F3, P<0.0001; F2 vs. F3, P=0.0177; F3 vs. cirrhosis, P<0.0001. The areas under the receiver operating characteristic curves of the time interval were 0.94, 0.96 and 0.98 for the diagnosis of marked fibrosis (≥F2), advanced fibrosis (≥F3) and cirrhosis respectively.

Conclusions: Contrast-enhanced US with Sonazoid™ may be a promising method for the indirect evaluation of hepatic fibrosis.