目的：应用MR灌注成像（PWI）评价兔肝纤维化分期的诊断价值。方法：在造模12周后对实验组（n=40）、对照组（n=10）分别进行MR灌注扫描，并对所得到峰值时间（TP），信号上升最大斜率、信号下降最大斜率与病理分期做对照，采用单因素方差分析（One-Way Anova），组间两两比较采用最小显著差法（LSD）。对不同时期的肝纤维化分期的诊断效能进行ROC曲线分析。结果：肝实质峰值时间随着肝纤维化程度的增加逐渐上升，而随着肝纤维化程度的增加信号上升最大斜率和信号下降最大斜率呈下降趋势，对于峰值时间，S0、S1、S2期与S3、S4期有统计学意义（P＜0.05），最大上升斜率两两比较后发现，S0、S2期与S3、S4期差异有统计学意义（P＜0.05）。最大下降斜率两两比较后显示，S0、S1、S2期与S3、S4期差异有统计学意义（P＜0.05）。合并纤维化分期进行比较（S0与≥S1，≤S1与≥S2，≤S2与≥S3，≤S3与S4）差异有统计学意义（P＜0.05）。结论：结合峰值时间和信号上升最大斜率能够反映肝纤维化各期灌注变化，对S2期以上的肝纤维化的诊断效能最佳。

Objective: To evaluate the diagnostic value of MR perfusion weighted imaging(PWI) for liver fibrosis in rabbit model. Methods: MR PWI was performed in the experimental group(n=40) and the control group(n=10). Time to peak(TP), wash-in rate and wash-out rate were compared with histological results by using one-way ANOVA Least significant difference(LSD) was used between two groups. The diagnostic efficiency of staging liver fibrosis was done by using ROC curve analysis. Results: With the deterioration of liver fibrosis, time to peak(TP) of liver parenchyma increased gradually, however, the wash-in rate and wash-out rate decreased. For TP, there was signifcant difference among stage S0~S2, S3 and S4(P<0.05). For wash-in rate, there was signifcant difference among stage S0 and S2, S3 and S4(P<0.05). Concerning wash-out rate, S3 and S4 stage can be distinguished from S0~S2 stage(P<0.05). After merging fibrosis stages, there was signifcant difference among stage S0 and ≥S1, ≤S1 and ≥S2, ≤S2 and ≥S3, ≤S3 and S4(P<0.05). Conclusion: Combining the TP and the signal rise maximum slope rate can reflect perfusion changes of liver fibrosis in different periods with highest diagnostic efficiency in stages over S2.