Genwen Hu1,2, Queenie Chan3, Xianyue Quan1, Xuhui Zhang1, Yufa Li4, Xing Zhong5, Xiaoying Lin2. 1. Department of Medical Image Center, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong Province, P.R. China. 2. Department of Medical Image Center, Shenzhen Bao'an Maternal and Child Health Hospital, Shenzhen, Guangdong Province, P.R. China. 3. Philips Healthcare, Hong Kong, P.R. China. 4. Department of Pathology, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong Province, P.R. China. 5. Department of Medical Image Center, First Affiliated Hospital, Jinan University, Guangzhou, Guangdong Province, P.R. China.
Abstract
PURPOSE: To explore the characteristics of intravoxel incoherent motion (IVIM) in various stages of liver fibrosis, and their relationships with fibrotic stages in rats. MATERIALS AND METHODS: Fifty rats were given various doses of carbon tetrachloride (CCl4 ) to induce various fibrotic stages in rats; 15 untreated rats served as controls. Diffusion-weighted magnetic resonance imaging (MRI) was performed and eight b-values (0-800 s/mm(2) ) were applied to obtain IVIM parameters (D, pure molecular diffusion; f, perfusion fraction; D*, pseudodiffusion). The stages of liver fibrosis (stages F0-F4) were evaluated histologically using METAVIR scores. Fifty-seven rats (15 controls and 42 with fibrosis) were analyzed by nonparametric methods and receiver operating characteristic curves to determine diagnostic accuracy. RESULTS: Significant differences (P < 0.001) were found between stages (stages F0-F4) by D, f, D*, and apparent diffusion coefficient (ADC). There were inverse correlations between fibrosis stages and D, f, D*, ADC (r = -0.657, r = -0.631, r = -0.711 r = -0.719, respectively). Multivariate analysis showed that the combination models (D, f, D*) were better than the individual parameter (ADC) for the evaluation fibrosis stages (area under the curve [AUC]: 0.821-1.000 vs. AUC: 0.753-0.918) CONCLUSION: IVIM-derived parameters showed significant correlations with stages of liver fibrosis in a rat model.
PURPOSE: To explore the characteristics of intravoxel incoherent motion (IVIM) in various stages of liver fibrosis, and their relationships with fibrotic stages in rats. MATERIALS AND METHODS: Fifty rats were given various doses of carbon tetrachloride (CCl4 ) to induce various fibrotic stages in rats; 15 untreated rats served as controls. Diffusion-weighted magnetic resonance imaging (MRI) was performed and eight b-values (0-800 s/mm(2) ) were applied to obtain IVIM parameters (D, pure molecular diffusion; f, perfusion fraction; D*, pseudodiffusion). The stages of liver fibrosis (stages F0-F4) were evaluated histologically using METAVIR scores. Fifty-seven rats (15 controls and 42 with fibrosis) were analyzed by nonparametric methods and receiver operating characteristic curves to determine diagnostic accuracy. RESULTS: Significant differences (P < 0.001) were found between stages (stages F0-F4) by D, f, D*, and apparent diffusion coefficient (ADC). There were inverse correlations between fibrosis stages and D, f, D*, ADC (r = -0.657, r = -0.631, r = -0.711 r = -0.719, respectively). Multivariate analysis showed that the combination models (D, f, D*) were better than the individual parameter (ADC) for the evaluation fibrosis stages (area under the curve [AUC]: 0.821-1.000 vs. AUC: 0.753-0.918) CONCLUSION: IVIM-derived parameters showed significant correlations with stages of liver fibrosis in a rat model.