Objective: The flow pattern in hepatic veins depends on cardiac physiology and liver histology. The aim of our study was to determine the dependence of the flow pattern of hepatic and portal veins in relation to histologic features in patients with chronic hepatitis C.
Subjects and methods: In 135 patients with chronic hepatitis C, the Doppler sonography spectrum of the right hepatic vein was classified as triphasic, biphasic, or monophasic. The flow of the portal vein was characterized according to the undulation (velocity(max,min)). A liver biopsy was performed during sonography, and biopsy specimens were semiquantitatively evaluated on a histologic activity index and a score of the hepatic fat content. Multiple logistic regression analysis was used to identify the histologic features that might contribute to the type of flow pattern.
Results: The hepatocyte fat content was the only variable associated with an independent effect on the type of flow pattern (monophasic versus triphasic; odds ratio, 16.26; 95% confidence interval, 6.38-41.45; p < .0001). A pronounced undulation in the portal vein was associated with portal inflammation but not with other parameters of the histologic activity index or the intrahepatic fat deposition.
Conclusion: On sonography, the normal flow pattern in the right hepatic vein is triphasic. The monophasic flow pattern in the right hepatic vein is mainly caused by intrahepatic fat deposition and occasionally by inflammatory or fibrotic changes. Conversely, the flow pattern of the portal vein is mainly influenced by portal inflammation.