Abstract: Objective To evaluate the MRI findings of primary biliary cholangitis patients with (PBC), and to explore the value of MRI in the diagnosis of PBC and the evaluation of liver fibrosis.Methods From Jan 2012 to Jan 2020, there were 42 patients with PBC (10 males and 32 females) with an average age of (52.9±9.8) years. T-test was used for measurement data, chi-square test was used for counting data, ROC curve was drawn, the best cut-off point for DWI diagnosis was determined, and the diagnosis of PBC staging by DWI was evaluated.Results According to Ludwig classification, there were seven cases of stage Ⅰ, twelve cases of stage Ⅱ, seventeen cases of stage Ⅲ and six cases of stage Ⅳ in patients with PBC. The MRI signs of the patients included diffuse hepatomegaly in 20 cases (47.6%), splenomegaly in 42 cases (100%), enlargement of portal vein lumen in 23 cases (54.8%), establishment of portosystemic collateral circulation in 4 cases (7.7%), ascites in 9 cases (21.4%), inhomogeneous signal intensity of hepatic parenchyma in 22 cases (52.4%), and T2-weighted high signal intensity around portal vein in 25 cases (59.5%). The periportal halo sign was found in 26 cases (61.9%), the number of intrahepatic bile ducts decreased in 24 cases (57.1%), and hilar lymph node enlargement in 24 cases (57.1%). Among the 26 PBC patients with periportal halo syndrome, there were two cases of stage Ⅰ (33.3%), four cases of stage Ⅱ (30.8%), fifteen cases of stage Ⅲ (83.3%) and five cases of stage Ⅳ (100%). Among the 24 patients with reduced number of intrahepatic bile ducts in PBC, there were zero cases in stage Ⅰ (0), four cases in stage Ⅱ (30.8%), fifteen cases in stage Ⅲ (83.3%) and five cases in stage Ⅳ (100%). There was significant difference in the number of cases in each stage (P<0.05), but no significant difference was found in other MRI signs (P>0.05). The average ADC values of patients with PBC were (1.12±0.04) ×10^-3 mm/s² in stage Ⅰ, (1.09±0.02)×10^-3 mm/s² in stage Ⅱ, (1.05±0.04)×10^-3 mm/s² in stage Ⅲ, and (1.01±0.03)×10^-3 mm/s² in stage IV, respectively. Comparing the average ADC value of each stage, there were significant differences between stage Ⅰ and stage Ⅲ, stage Ⅰ and stage Ⅳ, stage Ⅱ and stage Ⅳ (P< 0.05). The cutoff point, AUC (95%CI), sensitivity and specificity of DWI in patients with ≥stage Ⅱ PBC were 1.10× 10^-3 mm/s², 0.85 (0.78-0.89), 70.8% and 81.6%, respectively, and the cutoff point, AUC (95%CI), sensitivity and specificity in patients with ≥stage Ⅲ PBC were 1.06×10^-3 mm/s², 0.91 (0.85-0.94), 83.2% and 90.8%, respectively.Conclusion Periportal halo sign and decreased number of intrahepatic bile ducts are specific signs of MRI in patients with PBC. DWI can effectively diagnose patients with stage Ⅲ PBC. To sum up, MRI can be used as an effective non-invasive way to evaluate liver fibrosis in patients with PBC, and is helpful to evaluate the severity of PBC lesions.

Key words: Primary biliary cirrhosis, Magnetic resonance imaging, Hepatic fibrosis, Receiver operator characteristic curve