Assessment of Fibrotic Liver Regeneration After Partial Hepatectomy With Intravoxel Incoherent Motion Diffusion-Weighted Imaging: An Experimental Study in a Rat Model With Carbon Tetrachloride Induced Liver Injury

Abstract

PurposeTo determine whether intravoxel incoherent motion (IVIM) parameters correlate with liver regeneration and function recovery after partial hepatectomy (PH) in rats with carbon tetrachloride (CCl4)-induced liver fibrosis.MethodsSixty-two adult Sprague-Dawley rats were divided into the control group and the fibrosis group with CCl4 injection for 8 weeks. At the end of the 8th week, all rats received left lateral lobe liver resection. Within each group, IVIM imaging (n = 10/group) and histologic and biochemical analyses (n = 3/group/time point) were performed pre- and post-PH (on days 1, 2, 3, 5, 7, 14, and 21). Differences in liver IVIM parameters and correlation between IVIM parameters and Ki-67 indices, hepatocyte diameter, alanine transaminase (ALT), aspartate aminotransferase (AST), and total bilirubin (TBil) values were analyzed.ResultsPost-PH, liver true diffusion coefficient (D) values decreased and pseudodiffusion coefficient (D*) and perfusion fraction (PF) values increased, then recovered to pre-PH levels gradually in both fibrosis and control rats. PF in fibrosis group were significantly higher than in controls from 3 to 21 days (P < 0.05). In fibrosis rats, both Ki-67 indices and hepatocyte diameters increased, and a strong correlation was found between PF and Ki-67 indices (r = −0.756; P = 0.03), D* and PF values and ALT, AST, and TBil values (r = −0.762 to −0.905; P < 0.05). In control rats, only hepatocyte diameters increased, and all IVIM parameters correlated well with hepatocyte diameters, ALT, AST and TBil values (r = 0.810 to −1.000; P < 0.05).ConclusionThe regeneration pattern in fibrotic liver tissue was different compared with control livers. IVIM parameters can monitor liver regeneration and functional recovery non-invasively after PH.