Characterizing Fibrosis and Inflammation in a Partial Bile Duct Ligation Mouse Model by Multiparametric Magnetic Resonance Imaging.

backgroundPartial bile duct ligation (PBDL) model is a reliable cholestatic fibrosis experimental model that showed complex histopathological changes. Magnetic resonance imaging (MRI) features of PBDL have not been well characterized. PURPOSE: To investigate the potential of MRI parameters in assessing fibrosis in PBDL and explore the relationships between MRI and pathological features. ANIMAL MODEL: Established PBDL models. POPULATION: Fifty-four mice were randomly divided into four timepoints PBDL groups and one sham group. FIELD STRENGTH/SEQUENCE: 3.0 T; MRI sequences included T1-weighted fast spin-echo (FSE), T2-weighted single shot FSE, variable flip angle T1 mapping, multi-echo SE T2 mapping, multi-echo gradient-echo T2* mapping, and multi-b-value diffusion-weighted imaging. ASSESSMENT: MRI examination was performed at the corresponding timepoints after surgery. Native T1, ΔT1 (T1native-T1post), T2, T2*, apparent diffusion coefficient (ADC) values, histogram parameters (skewness and kurtosis), intravoxel incoherent motion parameters (f, D, and D STATISTICAL TESTS: One-way ANOVA, Spearman's rank correlation, and receiver operating characteristic curves were performed. P < 0.05 was considered statistically significant.

resultsFibrosis and inflammation were finally staged as F3 and A3 in ligated livers but were not observed in non-ligated or sham livers. Ligated livers displayed significantly elevated native T1, ΔT1, T2, and reduced ADC and T2 DATA

conclusionMultiparametric MRI can evaluate and differentiate pathological changes in PBDL. ΔT1 and ADC better correlated with fibrosis while T2 stronger with inflammation. LEVEL OF EVIDENCE: 1 TECHNICAL EFFICACY: Stage 2.