Caroli's disease: central dot sign re-examined by CT arteriography and CT during arterial portography

Caroli disease: review of eight cases with emphasis on magnetic resonance imaging features

BACKGROUND

Caroli disease is a rare congenital disorder characterized by segmental, nonobstructive dilatation of intrahepatic bile ducts. The term Caroli syndrome is used for the association of Caroli disease with congenital hepatic fibrosis.

STUDY AIMS

To provide an overview of the clinical presentation and imaging features of Caroli disease and syndrome, with an emphasis on magnetic resonance imaging.

PATIENTS AND METHODS

Retrospective analysis of medical records on eight patients in whom a histologic diagnosis of Caroli disease or syndrome had been made.

RESULTS

Presenting signs and symptoms were (hepato)splenomegaly, hematemesis and/or melena, cholangitis, jaundice, and recurrent fever. The central dot sign, defined in the literature as a dot or bundle of strong contrast enhancement within dilated intrahepatic ducts, was found in seven cases on various imaging modalities. A 'dot-like structure' was found in one case in which only unenhanced studies were available. There was a tendency toward a right hepatic-lobe predominance.

CONCLUSION

There is an overlap between the imaging features of Caroli disease and Caroli syndrome. Our findings support earlier reports that the central dot sign is highly specific for the disease, and that it can be reliably detected by current imaging techniques.

[Imaging in congenital fibrocystic diseases of the liver]

The identification of dilatations of the intrahepatic bile ducts in the absence of bile duct obstruction is rare. Imaging techniques, especially MR cholangio-pancreaticography, generally permit the distinction between fibrocystic liver diseases and polycystic liver diseases. The presence of dilated sacciform or tubular bile ducts on cholangio-pancreaticography associated with a centrally located fibrovascular bundle (central dot sign) suggests Caroli's syndrome. The presence of associated signs of liver dysmorphia including right lobe atrophy and hypertrophy of segment IV suggests associated congenital hepatic fibrosis. The findings on cholangio-pancreaticography, computerized tomography or Doppler ultrasonography correlate well with the pathogenesis of fibrocystic liver diseases, linked to an embryologic malformation of the ductal plate.