Todani classification of choledochal cysts
Type I is fusiform dilation of the extrahepatic duct (ED).
Type II is a true diverticulum of the supraduodenal ED.
Type III is an isolated choledochocele.
Type IV is fusiform dilation of the extrahepatic duct and intrahepatic ducts, and
type V is synonymous with Caroli disease.
