Acoustic Radiation Force Impulse And AST To Platelet Ratio Index Evaluation Of Liver Fibrosis In Rabbits

Objective To assess the value of the diagnosis of acoustic radiation force impulse (ARFI) elastography and AST to platelet ratio index (APRI) in a rabbit model for staging liver fibrosis.Methods Liver fibrosis models (model group) were established in32rabbits by subcutaneously infusing thioacetamide (TAA),8rabbits served as control group. Several rabbits in the model group and the control group were randomly selected and underwent ARFI elastography in order to obtain the shear wave velocity (SWV) respectively at the4th,8th andl2th week after the first injection. APRI by routine biochemical examination was calculated, and the rabbit’s liver for pathology analysis was taken. Histopathological staging of liver fibrosis served as the reference. The diagnostic performance of SWV and the APRI were compared by using ROC curve analysis.Results Among29successfully modeled rabbits,10,8,7and4rabbits were classified as S1, S2, S3and S4of liver fibrosis on pathology, respectively. The mean values of SWV and APRI were increased by degree with the exacerbation of liver fibrosis (P＜O.05). The SWV (r=0.724, P<0.05) and APRI (r=0.555, P<0.05) all showed correlation with fibrosis. The areas under the ROC curves for SWV and APRI were0.92and0.81for S≥1,0.87and0.78for S≥2,0.82and0.76for S≥3,0.89and0.79for S=4, respectively. The areas under the ROC curves for combination SWV and APRI in the diagnosis of S≥3was0.84, for the sensitivity was81.80%, the specificity was73.10%, the positive predictive value was56.23%, the negative predictive value was90.48%.Conclusion Both ARFI and APRI can provide accurate quantitative evaluation of liver fibrosis in rabbits. The ARFI is better for the diagnosis of liver fibrosis than the APRI.