Hepatic perfusion parameters of contrast-enhanced ultrasonography correlate with the severity of chronic liver disease

Abstract

In the study described here, we introduced a new ratio acquired with contrast-enhanced ultrasonography (CEUS): a liver parenchyma blood supply ratio that differentiates arterial and portal phases. Our purpose was to determine whether this ratio and other liver parenchyma perfusion parameters acquired with CEUS can be correlated with the severity of chronic liver disease. Twelve patients with non-cirrhotic chronic liver disease, 35 patients with cirrhosis (child class A: n = 10; child class B: n = 13; child class C: n = 12) and 21 healthy volunteers were examined by CEUS. Time-intensity curves were drawn for regions of interest located in liver parenchyma and right kidney cortex using QLAB quantification software. The arterial and portal phases were differentiated by the time to the maximum enhancement of right kidney and liver parenchyma perfusion data acquired from the time-intensity curves: the intensity of liver parenchyma perfused by hepatic arterial flow (I(ap)), the intensity of total perfusion of liver parenchyma (I(peak)), the intensity of liver parenchyma perfused by portal venous flow (I(pp)) and the ratio of portal perfusion to total perfusion of liver parenchyma expressed by the parameters I(pp)/I(peak), I(peak), I(pp) and I(pp)/I(peak) significantly decreased in patients with cirrhosis and in patients with non-cirrhotic chronic liver disease, whereas Iap increased. The parameters I(pp), I(peak), I(pp)/I(peak) and Iap correlated with the severity of chronic liver disease (r = -0.938, p < 0.001; r = -0.790, p < 0.001; r = -0.931 p < 0.001; r = 0.31, p < 0.05). The diagnostic accuracy rates for cirrhosis expressed as areas under receiver operating characteristic curves were 0.93 for I(peak), 0.98 for I(pp), 0.98 for I(pp)/I(peak), and 0.69 for I(ap). Liver parenchyma perfusion parameters obtained by CEUS were correlated with the severity of chronic liver disease and have the potential to assess cirrhosis non-invasively.

Keywords: Cirrhosis; Contrast-enhanced ultrasonography; Hepatic perfusion.