Computed tomography virtual endoscopy with angiographic imaging for the treatment of type IV-A choledochal cyst

Figure 1 Percutaneous transhepatic bile duct drainage cholangiography demonstrating a cystic dilatation of the common bile duct and relative stricture (arrow) between the extrahepatic and intrahepatic bile ducts.

Figure 2 Three-dimensional image. A: Three-dimensional (3D) frontal image demonstrating no stricture or dilatation of the anterior and lateral branches of the bile duct; B: 3D head image showing a relative stricture (*) and partial dilatation of the posterior branch of the bile duct. P: Percutaneous transhepatic bile duct drainage tube; GB: Gallbladder; Ant: Anterior branch; Pos: Posterior branch; Lat: Lateral branch.

Figure 3 Virtual cholangioscopy. A: Virtual cholangioscopy demonstrating a relative stricture of the orifice in the posterior branch (a) and no stricture in the anterior branch (b); B: Composite virtual cholangioscopy demonstrating no relationship between the membrane-like stricture and the surrounding blood vessels. Red indicates the hepatic artery and blue denotes the portal vein.

Figure 4 Operative findings. A: A membrane-like stricture, which was cut along the arrow line; B: Bile duct plasty was safely performed.