Objective: To investigate the ideal approach in creating rabbit model of hepatic fibrosis and to evaluate the feasibility and value of dynamic whole-liver 3D magnetic resonance (MR) perfusion-weighted imaging (PWI) in the quantitative study on the staging of hepatic fibrosis.
Methods: Rabbit model of hepatic fibrosis was created by intraperitoneal injection of 5% and 100% carbon tetrachloride (0.1 ml/kg, once a week) respectively. MR perfusion weighted imaging was performed at the 6th, 8th, 10th and 12th week since injection. The time of peak (TOP), the time to peak (TTP), the maximum slope of increase(MSI) and the maximal relative signal increase (MRSI) of portal vein and hepatic parenchyma were analyzed quantitatively, and were compared with pathological results. Comparison of different concentrations of CCl4 was analyzed using chi-square test. Inter-group comparison of perfusion parameters was analyzed using one-way ANOVA P less than 0.05 was regarded as statistically significant.
Results: 40% of the rabbits treated with 5% carbon tetrachloride developed hepatic fibrosis, while 75% of the rabbits treated with 100% carbon tetrachloride developed hepatic fibrosis; the mortality rate is significantly different between these two groups (X2=5.013, P less than 0.05). PWI examination was successfully achieved in 31 rabbits, liver perfusion baseline was stable, and good TIC curve was obtained. With the progress of hepatic fibrosis, TOP and TTP of portal vein and hepatic parenchyma were increased, and MSI and MRSI were decreased. There were significant differences among stage of S0-S2, S3 and S4.
Conclusions: The method (100% carbon tetrachloride intraperitoneal injection, 0.1 ml/kg, once a week) has high success rate of creating rabbit model of hepatic fibrosis. The stage of hepatic fibrosis could be evaluated quantitatively with dynamic whole-liver 3D MR perfusion-weighted imaging.