Real-time Tissue Elastography In Evaluating The Level Of Liver Fibrosis

Objective:To investigate real-time tissue elastography in evaluating the level of liver fibrosis induced by chronic hepatitis B virus and in order to be able to become a more objective noninvasive method to evaluate the degree of liver fibrosis.Methods:62 patients with chronic hepatitis B or hepatocirrhosis after hepatitis B from gastroenterology, infectious diseases, hepatobiliary surgical and 22 cases with chronic gastritis and without other diseases from gastroenterology of the First Affiliated Hospital of Guangxi Medical University were as the participants. The related clinical indicators of all participants collecting in wards were platelet, hemoglobin, red blood cells, total bilirubin, albumin, aspartate aminotransferase, alanine aminotransferase, liver function improved Child-Pugh classification. All participants were examined by routine ultrasound first and measured the relevant datas, hepatic portal vein diameter, hepatic portal vein flow velocity, hepatic artery flow velocity, resistance index of hepatic artery, pulsatility index of hepatic artery, splenomegaly or not, ascites with or without. Then, participants were scanned by real-time tissue elastography. The elasticity scores were defined as 0～4. (1) 62 participants with chronic hepatitis B or hepatocirrhosis after hepatitis B were divided into three groups (Ⅰ,Ⅱ,Ⅲ) according to the standard of liver function improved Child-Pugh classification. A comparative analysis was made between real-time tissue elastography scores and liver function improved Child-Pugh classification. (2) These serum fibrosis markers (collagen typeⅣ, hyaluronan, laminin, procollagen III N-terminal peptide, aspartate aminotransferase/alanine aminotransferase, that being AST-to-ALT ratio, AAR, aspartate aminotransferase/platelet, that being AST-to-platelet ratio, APRI)’s level of average and degree of variation were analyzed in different real-time tissue elastography scores. (3) Analyzing the correlation between real-time tissue elastography scores and serum liver fibrosis markers CIV, HA, LN, PⅢNP, AAR, APRI. Analyzing the serum hepatic fibrosis markers(CIV, HA, LN, PⅢNP, AAR)’s pairwise comparisons in different RTE scores. (4) The real-time tissue elastography scores as the dependent variable, and gender, age, splenomegaly or not, with ascites or not, hepatic portal vein diameter, hepatic portal vein flow velocity, hepatic arterial flow velocity, hepatic artery resistance index, hepatic artery pulsatility index, platelets, hemoglobin, red blood cells, total bilirubin, albumin, Child-Pugh classification, CIV, HA, LN, PⅢNP, AAR, APRI as independent variables, the method of multiple linear regression (stepwise method) analysis was used of finding out the relationship between real-time tissue elastography scores and these clinical and radiographic indicators.Results:(1) The real-time tissue elastography scores and improved Child-Pugh classification had a significant positive correlation cnzymes elevated (r=0.619 P=0.000). The real-time tissue elastography scores was increased when liver function severity increasing. (2) Serum liver fibrosis markers (CIV, HA, LN, P III NP, AAR, APPI)’s levle of average and degree of variation in different real-time tissue elastography scores were illustrated in the box graphs. Real-time tissue elastography scores were being increased when the serum markers (CIV, HA, LN, PⅢNP, AAR, APRI)’s level of average were increasing. There were outliers in serum markers CIV, HA, LN, PⅢNP, AAR, APRI. The data points of serum markers LN、PⅢNP、AAR、APRI were more concentrated. (3) In different real-time tissue elastography scores, serum liver fibrosis markers CIV, HA, LN, PⅢNP, AAR have statistically significant (χ2= 14.96、22.69、18.40、18.31、15.45、P<0.05) and the APRI did not (χ2=7.22, P>0.05). The real-time tissue elastography scores and serum liver fibrosis indexes had a positive correlation. The correlation between real-time tissue elastography scores and indicators CIV, HA, LN, PⅢNP, AAR were statistically significant(r= 0.49、0.60、0.53、0.54、0.46、P<0.001), correlation coefficient being moderate. Serum liver fibrosis markers (CIV, HA, LN, PⅢNP, AAR)’s pairwise comparison in different RTE scores showed that:the serum liver fibrosis markers CIV, HA, LN, PⅢNP, AAR were not statistically significant between RTE score being 0 and 1; the serum liver fibrosis markers CIV, HA, LN, PⅢNP, AAR were not statistically significant between RTE scores being 1 and 2; the corresponding some or all of serum liver fibrosis indicators had statistical significance in the rest of the RTE scores. (4) Multiple linear regression analysis obtained that the residuals was with the normality and variance of homogeneity. Multiple linear regression analysis obtained five independent variables, namely, hyaluronic acid, age, hepatic portal vein flow velocity, AAR, gender in accordance with the regression equation finally (P<0.001), so the real-time tissue elastography scores were close with hyaluronic acid, age, hepatic portal vein flow velocity, AAR, gender. The non-standard regression coefficients were 0.002、0.032、-0.044、0.485、-0.916 respectively, so including factors of gender, the higher the level of hyaluronic acid, the older, the greater the AAR value, the higher the real-time tissue elastography scores; and the higher the hepatic portal vein flow velocity, the lower the real-time tissue elastography scores. The standardized regression coefficients of the equation were 0.320、0.351、-0.238、0.257、-0.280 respectively, so the order according to the five indicators’s contribution to the regression equation in descending was age, hyaluronic acid, sex, AAR, hepatic portal vein flow velocity. And age was the most important influence factor to real-time tissue elastography scores, following hyaluronic acid, and the smallest influence factor was hepatic portal vein flow velocity.Conclusions:Real-time tissue elastography provides a new method in diagnosing the degree of liver fibrosis, would have a unique advantage and broad application future prospect, would be a useful supplement method to diagnose the level of liver fibrosis and was being expected to become a noninvasive, more objective method to evaluate the degree of liver fibrosis.