Abstract: Objective The aims of this study was to explore the diagnostic efficacy of significant liver fibrosis by apparent diffusion coefficient (ADC) in patients with primary sclerosing cholangitis (PSC).Methods A total of 68 patients with PSC were included in this study in our hospital between August 2010 and December 2020, and all patients underwent liver biopsies and MR scan. The liver fibrosis was estimated by METAVIR staging scoring system, and the hepatocellular uptake rate (Ki), extracellular volume (Ve), portal venous flow (Fv) and arterial flow (Fa) were obtained from MRI, calculating the total blood flow (Ft), extracellular mean transit time (MTT) and hepatic uptake fraction (Fi). The apparent diffusion coefficient (ADC) was also determined. The univariate and multivariate Logistic regression analysis was applied to reveal the impacting factors of liver fibrosis in PSC patients. The area under the receiver operating characteristic curve (AUROC) was applied to analyze the diagnostic efficacy of each parameter.Results Out the 68 patients with PSC, the liver histopathological examination showed that non-significant liver fibrosis staging F0/F1 was in 24 cases, and significant liver fibrosis staging F2/F3/F4 was in 44 cases; there were significant differences as respect to serum ALT, AST, ALP, GGT, bilirubin, INR, IgG as well as Ki, Fi and ADC (P<0.05); the multivariate Logistic regression analysis demonstrated that serum ALT, AST, ALP, GGT, INR, IgG, and Ki and ADC were the independent impacting factors for liver fibrosis (P<0.05); the ROC analysis showed that the sensitivity and specificity by Ki in diagnosing significant liver fibrosis were 70.5% and 58.3% when the Ki=3.5/100 min was set as the cut-off-value, and those by ADC were 90.9% and 83.3% when it equal to 1.14 s/mm² as the cut-off-value.Conclusion The application of ADC in predicting liver fibrosis in patients with PSC is promising, and warrants further investigation.

Key words: Primary sclerosing cholangitis, Dynamic contrast-enhanced magnetic resonance imaging, Diffusion-weighted imaging, Apparent diffusion coefficient, Diagnostic trial