Abstract: Objective To investigate MR diffusion-weighted imaging（DWI） in the diagnosis of hepatic fibrosis in rabbits. Methods Rabbits with CCl₄-induced liver fibrosis was established. 7 or 8 rabbits in model group and 2 or 3 rabbits in control group were sacrificed at each attempt,and a total of 30 rabbits in model and 10 rabbits in control group had DWI checked-up. Apparent diffusion coefficient（ADC） values of liver with different b values （b=300,500 and 1000 s/mm²,respectively） were calculated. The rabbits were sacrificed 12h after DWI scanning and the liver tissues were examined pathologically. Spearman correlation analysis was conducted to reveal the correlation between ADC values and fibrosis staging,and receiver operating characteristic （ROC） curve was used to assess the performance of ADC values in predicting the presence of ≥2 stage and ≥3 stage of hepatic fibrosis. Results There was a negative correlation between hepatic ADC values and fibrosis stage,and the optimal correlation was obtained with a b value of 500 s/mm²（r=-0.697,P=0.000）;There was a significant difference in hepatic ADC values between rabbits with ≤1 stage and ≥2 stage of fibrosis,as well as between ≤2 stage and ≥3 stage of fibrosis（P<0.05 for both） no matter at b=300,500 and 1000 s/mm²;When b value=500 s/mm²,the areas under the receiver operating characteristic curves（AUC） in discriminating ≥2 stage of fibrosis by ADC values were 0.912,given ADC value=1.58×10^-3mm²/s as cut-off value,and the sensitivity and the specificity were 90.2% and 75.0%,respectively;while in discriminating ≥3 stage of fibrosis,the AUC were 0.920 with ADC of 1.43×10^-3mm²/s as cut-off value,and the sensitivity and the specificity were 93.0% and 80.0%,respectively. Conclusion The hepatic ADC values can be employed tentatively in determining fibrosis staging and is expected to be a new approach for the diagnosis of hepatic fibrosis.

Key words: Liver fibrosis, Magnetic resonance imaging, Diffusion weighted-imaging, Diagnosis, Rabbits