[Magnetic resonance imaging features and classification of intraductal papillary neoplasm of the bile duct].

Objective: To explore the magnetic resonance imaging (MRI) features and classification of intraductal papillary neoplasm of the bile duct (IPNB). Methods: Data from 90 patients with intraductal papillary neoplasm of the bile duct confirmed pathologically between June 2010 and January 2023 were retrospectively analyzed. The image analysis included the shape and location of the tumor, whether bile ducts had dilatation and the degree of dilation, whether there was a history of liver disease, whether there was a history of schistosomiasis, whether there was cancerous transformation, whether there were concurrent bile duct stones, whether there was hepatic lobe atrophy, whether there was hilar or abdominal lymph node enlargement, whether there was invasion of the bile duct wall, whether there was invasion of surrounding blood vessels, whether the tumor appears on T1-and T2 weighted imaging (T(1)WI and T(2)WI), whether the diffusion was limited, whether there was concurrent bleeding, enhancement rate, and whether there was abdominal fluid accumulation. Intraductal papillary neoplasms of the bile duct were divided into four types according to the morphological classification standards: type I (local bile duct dilation), type II (cystic), type III (free tumor), and type IV (dilated bile duct). The differences in the clinical and MRI features of the four groups of lesions were analyzed. Statistical analysis was performed with a t-test, an analysis of variance, and an χ(2)-test according to the different data. Results: Among the 90 cases with hepatic IPNB, there were 31 cases of type I, 15 cases of type II, 16 cases of type III, and 28 cases of type IV, 41 cases of liver left lobe, 11 cases of right and left lobe liver span, 7 cases of liver right lobes, 2 cases of liver caudate lobe, and 13 cases of hepatic hilar. There were statistically significant differences between the four groups (P < 0.05) in terms of age, clinical symptoms, direct bilirubin, γ-glutamyltransferase, whether they were cancerous, whether they were combined with bile duct stones, whether the liver lobes were atrophying, whether there was limited diffusion, intrahepatic bile duct diameter, and common bile duct diameter. However, there were no statistically significant differences among the four groups in gender, location, carbohydrate antigen 19-9, history of liver disease, history of schistosomiasis, carcinoembryonic antigen, alanine aminotransferase, aspartate aminotransferase, total bilirubin, whether hemorrhage was associated, lesion enhancement rate, whether the hilar/retroperitoneal lymph node was enlarged, whether the bile duct wall was invaded, whether blood vessels were invaded, and whether abdominal fluid was accumulated (P > 0.05). Conclusion: MRI manifestations have certain features for different types of intraductal papillary neoplasm of the bile duct tumors; hence, MRI aids in the diagnosis and differential diagnosis of this disease.