Variably distributed (diffuse, lobar, or segmental)

• ERCP: Dilatation (usually saccular) of large intrahepatic ducts with alternating biliary strictures







IMAGING
General Features
• Morphology
Segmental saccular dilatation of large intrahepatic bile ducts separated by normal or dilated bile ducts

MR Findings
• T1 hypointense, T2 hyperintense, nonenhancing cysts variably distributed in liver
Due to communication with biliary tree, cysts fill with contrast in hepatobiliary phase when using hepatobiliary contrast agent (e.g., gadoxetate [Eovist])

Ultrasonographic Findings
• Dilated intrahepatic bile ducts: Communication between cysts and biliary tree may be difficult to demonstrate on US
• Echogenic septa may completely or incompletely traverse dilated lumen of bile ducts (intraductal bridging sign)
• Small portal venous branches may be partially or completely surrounded by dilated IHBD (US correlate of central dot sign
DIFFERENTIAL DIAGNOSIS
AD Polycystic Hepatic Disease
Recurrent Pyogenic Cholangitis
• Disease characterized by formation of pigment stones throughout biliary tree, with resultant biliary strictures and repeated bouts of cholangitis
• Dilatation of both intra- and extrahepatic bile ducts, usually of cylindrical morphology (not saccular)
PATHOLOGY
General Features
• Etiology
• Genetics
• Embryological anatomy
Ductal plate malformation: Incomplete remodeling of ductal plate leading to persistence of embryonic biliary ductal structures

CLINICAL ISSUES
Presentation
• Most common signs/symptoms









































