Research On Fibrosis Stage Evaluation Of Chronic Liver Disease By Contrast Enhanced Ultrasonography

Objective : To assess the value of real time gray scale contrast-enhanced ultrasonography in differentiating the chronic liver disease by measuring the hepatic artery to vein transit time (HAVTT) and analyzing the time intensity curve (TIC) of liver parenchymal enhancement.Methods:20 normal volunteers and 60 patients with chronic liver disease were enrolled in this study. First, real time gray scale contrast-enhanced ultrasonography was performed to measure HAVTT by a bolus injection of 0.6ml SonoVue. The values of hepatic artery arriving time (HAAT), hepatic vein arriving time (HVAT) and hepatic vein obviously increase time (HVOIT) were measured by both directly visualization method and TIC analysis method, and then calculated HAVTT1 (HVAT subtract HAAT) and HAVTT2 (HVOIT subtract HAAT). Compared the average value of HAVTT among the different fibrotic stages and assessed the correlation between the HAVTT and the hepatic fibrosis degree. Second, 37 patients with chronic liver disease and 1 normal volunteer underwent real time gray scale contrast-enhanced ultrasonography to assess the liver parenchyma enhancement by TIC analysis. The parameters of arrival time (AT), time to peak (TP), peak intensity (PI), ascending slope (AS), descending slope (DS), half time of descent (HTD) and area under the curve (AUC) were measured and compared.Results:1. The mean values of HAAT,HVAT,HVOIT,HAVTT1 and HAVTT2 measured by these two methods were not significantly different,and there was a positive correlation between these two methods (r=0.97, P<0.001 and r=0.98, P<0.001). 2. The HAVTT values were remarkably different among the three groups (the non-fibrosis group, the fibrosis group and the cirrhosis group) and there was an inverse correlation between HAVTT and the fibrosis degree (r=-0.80). 3. TP, PI, DS, HTD and AUC in liver cirrhosis group were shorter than those in liver fibrosis group with statistical significance (P<0.05). Conclusions:1. The parameter measured by directly visualization method has a higher successful rate than the TIC analysis method, the former method is more simple, reliable and practical, what is more, it is less influenced by the breath motion. And HVOIT which has a higher successful rate than HVAT is a good parameter to measure HAVTT.2. HAVTT and TIC analysis of liver parenchyma detected by real time gray scale CEUS can reflect the changes of hepatic microcirculation and hemodynamics that occur in the patients with chronic liver disease, which could help to judge the hepatic fibrosis degree and to diagnose the hepatic cirrhosis in an early stage. It is promising that the combination usage of HAVTT and TIC analysis will become a noninvasive new way to diagnose the chronic liver disease.