Diagnostic Ultrasound - Abdomen and Pelvis

Caroli Disease
Diagnoses: Liver
TERMINOLOGY
• Caroli disease: Congenital, multifocal, segmental, cystic
dilatations of intrahepatic bile ducts
• Caroli syndrome: Cystic bile duct dilatation with hepatic
fibrosis
IMAGING
• Segmental saccular dilatation of large intrahepatic bile
ducts
• "Central dot" sign: Characteristic finding
○ Echogenic dots with color flow within cystic lesion on
US/color Doppler US
○ Enhancing portal radicles within dilated intrahepatic bile
ducts on CECT/MR
TOP DIFFERENTIAL DIAGNOSES
• AD polycystic liver disease
• Recurrent pyogenic cholangitis
• Primary sclerosing cholangitis
KEY FACTS
• Ascending cholangitis
• Biliary hamartoma
PATHOLOGY
• Etiology:Incomplete remodeling of ductal plate leading to
persistence of embryonic biliary ductal structures
○ Caroli disease: Malformation of large-sized ducts (more
common in adults)
○ Caroli syndrome: Malformation of large- and small-sized
ducts (more common in children)
• Todani classification of congenital bile duct cysts: Type V
CLINICAL ISSUES
• Symptoms/signs: Related to cholangitis and hepatic fibrosis
DIAGNOSTIC CHECKLIST
• Rule out other liver diseases, which have hepatic cysts
±dilated bile ducts
(Left) Transverse graphic
shows focally dilated
intrahepatic ductules ſt
running adjacent to portal
venules in Caroli disease. The
dilated ductule may encircle
the adjacent vein, creating
a "central dot" sign
appearance on cross-sectional
imaging. (Right) Gross
photograph of the liver shows
clusters of dilated and cystic
intrahepatic bile ducts ſt.
(From: DP Nonneoplastic
Pediatrics.)
(Left) Oblique abdominal
ultrasound in a young patient
with Caroli disease shows
multiple dilated intrahepatic
ducts ſt. Echogenic portal
radicles are surrounded by
dilated ducts. (Right) Oblique
abdominal color Doppler
ultrasound in the same patient
shows color flow in portal
radicles surrounded by
dilated intrahepatic ducts ſt,
which creates the "central
dot" sign appearance.
204
http://radiologyebook.com/