A Preliminary Study Of Sound Touch Elastography In Evaluating Nonalcoholic Fatty Liver Disease

ObjectiveUse sound touch elastography(STE)to evaluate nonalcoholic fatty liver disease(NAFLD),to explore the related factors of Young’s modulus,and to analyze the efficacy and cut-off of STE in the diagnosis of low and high risk NAFLD.Methods37 NAFLD patients who underwent liver biopsy from January 2019 to January 2021 were selected as the NAFLD group and 33 healthy volunteers were selected as the control group in this study.The NAFLD group was further divided into low-risk group(F<2)and high-risk group(F≥2)according their stages of liver fibrosis.We calculated the Young’s modulus in liver using STE and collected general information and relevant laboratory tests for all study subjects.We analyzed the difference of general information,relevant laboratory tests and Young’s modulus among 3 groups and used Spearman correlation analysis to explore the correlated factors of Young’s modulus.The area under the receiver operating characteristic(ROC)curve was used to evaluate the efficacy of STE in diagnosing high-risk NAFLD.Results1.There were statistically significant differences in Young’s modulus among control group,low-risk NAFLD group and high-risk NAFLD group(H=31.417,P=0.000).The Young’s modulus of high-risk NAFLD group was 8.45(7.67,11.40)k Pa which was significantly higher than that of low-risk NAFLD group 6.61(5.84,7.08)k Pa and control group 6.08(5.70,6.81)k Pa(P<0.05).There was no significant difference in Young’s modulus between low-risk NAFLD group and control group(P>0.05).There was significant difference in liver fibrosis stage and inflammatory activity grade between low-risk NAFLD and high-risk NAFLD(P<0.05),but there was no significant difference in steatosis grade(P>0.05).2.Weight,body mass index(BMI),alanine aminotransferase(ALT),aspartate aminotransferase(AST),gamma-glutamyl transferase(GGT),total cholesterol(TC),triglyceride(TG),low density lipoprotein(LDL),C-Peptide(C-P),insulin(INS),liver fibrosis stage and inflammatory activity grade were correlated with Young’s modulus(P<0.05).Among them,liver fibrosis stage has the highest Spearman’s correlation coefficient(r=0.798,P=0.000).3.The area under the receiver operating characteristic curve of STE for high-risk NAFLD diagnosis was 0.89,better than that of ALT(AUC=0.699),AST(AUC=0.778),direct bilirubin(DBIL)(AUC=0.522),INS(AUC=0.616)and AST to platelet ration index(APRI)(AUC=0.756).When the cut-off was 7.34 k Pa,the sensitivity was 0.85 and the specificity was 0.87.4.Used Logistic regression to analyze the factors that are clinically associated with high-risk NAFLD,Young’s modulus was statistically significant(OR=6.608,P=0.008).Conclusion1.This study confirms that STE can diagnose and evaluate NAFLD quantitatively.Young’s modulus of high-risk NAFLD were significantly higher than that of low-risk NAFLD.2.Weight,BMI,ALT,AST,GGT,TC,TG,LDL,C-P,INS,liver fibrosis stage and inflammatory activity grade were correlated with Young’s modulus.Among them,liver fibrosis stage had the highest Spearman’s correlation coefficient.3.STE outperforms laboratory tests in identifying low and high-risk NAFLD patients with a good diagnostic efficacy.When the cut-off was 7.34 k Pa,the sensitivity was 0.85 and the specificity was 0.87.