Real-time tissue elastography with tissue dispersion quantitative analysis technique for assessment of rat liver fibrosis

Abstract

Objective To explore the value of real-time tissue elastography (RTE) with tissue dispersion quantitative analysis technique for assessment of liver fibrosis stage.Methods 51 rats were injected 6％ thioacetamide to induce liver fibrosis model,and 9 rats were injected saline as control group.In modeling 4 weeks,8 weeks,12 weeks respectively,14 rats in group of liver fibrosis model and 3 rats in control group were randomly selected to RTE.All the rats underwent tissue dispersion quantitative analysis,to obtain 12 quantitative parameters of elasticity,which included average relative strain value (MEAN),standard deviation of relative strain value (SD),area ratio of low-strain region (％ AREA),complexity (COMP),kurtosis (KURT),skewness (SKEW),contrast (CONT),entropy (ENT),inverse difference moment (IDM),angular second moment (ASM),correlation (CORR) and liver elasticity index (LF index).Subsequently,rats were sacrificed and their livers were taken for pathology analysis.Liver fibrosis model group was divided into S0,S1,S2,S3,S4 group.The 12 quantitative parameters of elasticity were compared with each group.Results 49 rats were successfully modeled,and 42 rats were analyzed.Except COMP,KURT,CORR,the other quantitative parameters had statistically differences (P ＜ 0.05).The other 9 parameters were correlated with liver fibrosis stage.Among these parameters,MEAN,％ AREA and LF index had higher related coefficient(r =-0.831,0.882,0.866).The ROC curve was made by MEAN,LF index and ％AREA to estimate the fibrosis stage,when S≥S1,S≥S2,S≥S3,S =S4,the areas under the ROCcurve were 0.884,0.925,0.934,0.962 (MEAN);0.917,0.958,0.984,0.962 (％AREA);0.917,0.948,0.966,0.967 (LF index),respectively.Conclusions As a non-invasive examination,RTE dispersion quantitative analysis technology can be used to quantitatively assess liver fibrosis. Key words: Ultrasonography; Liver cirrhosis,experimental; Elastography