Abstract: Objective The aim of this study was to summarize magnetic resonance cholangiopancreatography (MRCP) and multi-slice spiral CT (MSCT) feature in children withcongenital choledochal cysts (CCC). Methods 89 children with CCC were encountered in our Children's Hospital Affiliated to Soochow University between February 2019 and December 2024, and all underwent MRCP and MSCT scan. Results By MRCP, the common bile duct of children with CCC was accompanied by varying degrees of cystic, fusiform or columnar dilation, and Todani type I accounted for 77.5% (type Ⅰa in 63 cases,Ⅰb in 3 cases and Ⅰc in 3 cases, and type Ⅱ in 10 cases(11.2%), type Ⅲ in 2 cases (2.2%) and type Ⅳ in 8 cases (9.0%); MSCT scan diagnosed that Todani typeⅠ in 70 cases(78.7%), Todani typeⅠa in 64 cases, typeⅠb in 3 cases and type Ⅰc in 3 cases), and Todani type Ⅱ in 9 cases (10.1%), Todani type Ⅲ in 3 cases (3.4%) and Todani type Ⅳ in 7 cases(7.9%). Conclusion MRCP and MSCT scan could reveal the location, Morphology and structure of the bile duct system in children with CCC, which provide a basis for the clinical diagnosis and management.

Key words: Congenital choledochal cyst, Magnetic resonance cholangiopancreatography, Multi-slice spiral CT scan, Imaging feature, Children