Abstract: Objective To observe the CT and MRI features of cystic intraductal papillary neoplasms of the bile duct (IPNB). Methods 90 patients with cystic IPNB were retrospectively analyzed, another 90 patients with mucinous cystic tumor (MCN) were selected as MCN group. The clinical data and imaging features of the two groups were analyzed. At the same time, IPNB group was divided into invasive lesions (51 cases) and non-invasive lesions (39 cases) according to the pathological results. Results The proportion of mural nodules, bile duct communication and bile duct dilatation in IPNB group (63.33%, 51.11%, 100.00%) was significantly higher than that in MCN group (17.78%, 0.00%, 17.78%) (P<0.05). In IPNB group, the diameter of invasive lesions [(7.49±0.68) cm] was significantly higher than that of non-invasive lesions [(5.53±0.46) cm] (P<0.05). Conclusion In CT and MRI imaging features, mural nodules, bile duct communication and bile duct dilatation can be used as the basis for clinical diagnosis and differential diagnosis of cystic IPNB. In addition, the larger the diameter of cystic IPNB, the higher the possibility of invasive lesions.

Key words: Cystic type, Intraductal papillary neoplasms of the bile duct, CT, MRI, Imaging features