Abstract：Objective: To evaluate the diagnostic efficacy of diffusion-weighted MR imaging for liver fibrosis. To investigate the correlation between apparent diffusion coefficient(ADC) value and serum markers of liver fibrosis. Methods: Thirty-eight Wistar rats developed experimental model of liver fibrosis by carbon tetrachloride(CCl4) hypodermic injected and ten rats as control group were performed MR scans and MR-DWI. Grouping according to different stage of fibrosis, the results of DWI signal intensity(SI) and ADC were compared with different b values(333, 666 and 1000s/mm2). Blood samples were obtained after MR examination to observe serum markers of liver fibrosis including hyaluronic acid(HA), procollagen type Ⅲ(PC Ⅲ), type Ⅳ collagen(C-Ⅳ) and laminin(LN). The differences of results at various stages of liver fibrosis were compared. Analysis of relationships among serum markers and stage of liver fibrosis were performed. Results: Grouping according to different stage of fibrosis, S0(n=3), S1(n=5), S2(n=9), S3(n=13), S4(n=8). When b values equal to 333, 666 and 1000s/mm2 respectively, SI increased and ADC decreased gradually as the stage of fibrosis progressed(P<0.01). There was a good relationship between ADC and stage of fibrosis, especially when b value was 1000s/mm2. When b value equal to 333 and 666s/mm2, S0～S2 can be distinguished from S3 and S4 stage, and S3 can be distinguished from S4 stage according to SI and ADC values. Moreover b value equal to 1000s/mm2, S0～S2 can be distinguished from S4 stage. There was excellent negative correlation between ADC and serum indices(P<0.05). Conclusions: DWI would be a useful criterion for detecting liver fibrosis on S3 and S4 stage, but having limitation to detect early fibrosis(S0～S2 stage). Excellent correlation between ADC value and serum indices reflects the characteristic pathologic state of abnormal synthesis and deposition of extracellular matrix.
2009, Vol. 20 
