Correlation Research Of Virtual Touch Tissue Quantification And Pathology On Liver Fibrosis Model In Rats

BackgroundHepatic Fibrosis (HF) is an excessive repair response to chronic liver damage in the liver dueto various reasons. It is an intermediate process of chronic liver disease to Cirrhosis[1,2]. EarlyHepatic Fibrosis can be reversed if give effective treatment.Early diagnosis and treatment canprevent or stop the process and reduce the chance of Cirrhosis and Liver Cancer[3,4]. Currently,Liver Biopsy and pathological diagnosis is the gold standard for diagnosis of HF[5]. However,Liver Biopsy is an invasive examination with certain risks[6,7]. To find an accurate, reliable andnoninvasive method for the diagnosis of HF is necessary and urgently[8,9]. It can provide help fordiagnosis and evaluate the effect of the treatment for HF. In recent years, with the significantdevelopment of ultrasound diagnostic techniques, Ultrasonic Elastography (UE) receives widelyconcern. It is an objective, non-invasive technique to exam the liver and can restore the liveraffected area and liver morphological characteristics vividly. It is expected to become the newnon-invasive means of diagnosis of HF and early Cirrhosis replacing Liver Biopsy.PurposesOur research apply Siemens Acuson S2000(German) Color Doppler ultrasound using theVirtual Touch Tissue Quantification (VTQ) technique to examine a rat Hepatic Fibrosis model, andtry to diagnose the degree of Hepatic Fibrosis in rats. Analyze the correlation of VTQ andSerological Test results. By using pathological diagnosis as gold standard, we aim to find out theaccuracy, sensitivity of the VTQ examination and provide basic research of clinical applicationbase on ARFI technique.Method1. We build Hepatic Fibrosis animal model with50SD rats using4%Thioacetamide (TAA)under ultrasound monitoring（model group45，control group5）. Using4%TAA1ml for the firstinjection as a induction dose and adopt abdominal subcutaneous inner thighs. We adjust the dose to200mg/kg from the second induction. Weighing and examine weekly with ultrasound. Adjust thedose based on ultrasound examination results. Randomly selected15rats from model group, and2from the control group, execute and take blood test after ultrasound examination. Take the liver outfor histological analysis. Execute all the remaining animals12w all were sacrificed in the sameway. 2. Rat percutaneous anesthesia checked by Acuson S2000color Doppler Ultrasound (madein Germany) using Virtual Touch Tissue Quantification (VTQ) technique and eSie touch technique.Gather and analyze the data of the hepatic fibrosis. All data was taken from the right lobe of theliver organization and tried to elastography region of interest as far as possible to avoid the lobeboundary between and intrahepatic blood vessels. Measure7times for each selected rat indifferent regions.3. We checked the biochemical indices (ALT and AST, HA, LN and IV-C, etc.) for each rat.using Evaluate the sensitivity and specificity of the VTQ technique for checking Hepatic Fibrosismodel using histopathological findings and score as the gold standard. On this basis, we investigatethe accuracy and diagnostic value of eSie touch and VTQ technique on classifying of liver fibrosisinstallments in rats.Results1. Animal modeling success: Model group45cases, Control group4cases.5cases diedduring modeling in model group,3cases (60%) died in5w, suggesting induction failure. No deathcases in6w-8w.2deaths occurred in9w-12w because of significantly liver dysfunction.Successful modeling in12w: S1-S2:12cases, S3-S4:11cases, cirrhosis:14cases. Total successfulmodeling:36cases, with a success rate of90%, all successful cases have been put into theexperimental study.2. Pathological result: Model group livers swelling and have a dark red color shallow thannormal liver. Cirrhosis model group livers are smaller, lost their luster and have a harder texture.Their surfaces are uneven, showing granular change, in line with cirrhosis performance. HE andMasson trichrome staining results indicate a successful modeling and in accordance with therequirements of the experimental design.3. Serological data of Hepatic Fibrosis in different stages: The serological fibrosis indicatorsincreased with fibrosis stage elevated and reach a peak when cirrhosis occurred. Normality testshows the distribution of AST, ALT, IV-C, the HA does not meet the normal distribution, whilethe LN fit the normal distribution.4. VTQ Test show:36cases of liver fibrosis/cirrhosis cases and5cases control VTQ result:The VTQ value measured minimum0.79, maximum3.56. Control group:1.25±0.20, group A1.52±0.22, group B1.89±0.18, and group C2.45±0.34. Variance analysis indicated that there isstatistically significant between each group. Control, Group A, Group B and Group C has a verygood distribution range with each other.5. The VTQ results were positively correlated with ALT, IV-C and VTQ indicators, butcorrelation is not strong, correlation coefficients were0.3-0.4. AST, HA indicators were not andcorrelated with VTQ, respectively P＞0.05. 6. Compared VTQ result and pathological gold standard, we can build a discriminant equationY=3.519*VTQ03+3.302*VTQ07-12.813. We use back to the generation of validation andcross validation methods to verify the discriminant function, the results show back to thegeneration of validation and cross validation of the discriminant accuracy rate was92.3%.Conclusion1. Establishing SD rats HF model with injection of TAA under ultrasound monitoring wassuccessful, animal mortality rate was10%, model rate was90%. This modeling method is moreeffective than traditional methods group. TAA induction dose adjusted according to ultrasoundelastography results can successfully induced rat liver fibrosis, reducing the mortality of rats, andsignificantly increase the rate and quality of hepatic fibrosis modeling.2. The in vivo experiment carried out by rat liver fibrosis model shows: To diagnosis rat liverfibrosis with ultrasound VTQ techniques is feasible. VTQ values and liver biochemical markers arenot close correlated. Comparative study using pathological diagnosis as a standard showed that wecan build a discriminant equation: Y=3.519.*VTQ03+3.302*VTQ07-12.813. We use back tothe generation of validation and cross validation methods to verify the discriminant function, theresults show back to the generation of validation and cross validation of the discriminant accuracyrate was92.3%, with high accuracy.