A 49-year-old woman presented with longstanding, intermittent episodes of mild abdominal pain in the right upper quadrant. Clinical examination revealed a mild hepatomegaly, without splenomegaly or signs of portal hypertension. An abdominal ultrasound performed in the diagnostic work-up identified multiple liver cysts (Fig. 1A). She was further referred to our institution for a magnetic resonance (MR) examination, which confirmed the findings of multiple intrahepatic cysts in close relation to the biliary tree, some of them with the central dot sign, which represents a central fibrovascular bundle within the lesion (Fig. 1B,C). Contrast-enhanced MR cholangiography using hepatospecific contrast agent (gadoxetic-acid-disodium, Gd-EOB-DTPA), in the late hepatobiliary phase (biliary excretion of contrast agent, 2h after contrast agent injection), showed filling of the cystic spaces by the contrast medium (Fig. 1D), allowing to prove the communication between these cysts and the intrahepatic biliary tree and, consequently, a confident diagnosis of Caroli disease (CD).
Ultrasound image (A) demonstrates multiple intrahepatic cysts (arrows). Coronal conventional T2-weighted MR cholangiography (B) and axial pre-contrast T1-weighted MR image (C) confirm the finding of multiple liver cysts in close relation to the biliary tree (arrows), some of them with the central dot sign (B). Late hepatobiliary phase of contrast-enhanced MR cholangiography using gadoxetic acid (D) demonstrates filling of cysts by contrast agent (arrows), proving their communication with the biliary tree and adding complementary information supportive of a diagnosis of Caroli disease.
Caroli disease is a rare congenital disorder characterized by non-obstructive, saccular or fusiform dilatation (focal or diffuse) of the intrahepatic biliary ducts.1 The conventional MR cholangiography findings of multiple intrahepatic cysts in close relation to the biliary tree in diffuse CD, as in our case, have to be differentiated from autosomal-dominant polycystic liver disease and peribiliary cysts, among other alternative diagnoses.1 Although the central dot sign is another clue for the diagnosis of CD on conventional MR cholangiography,1 it has also been described in other diseases.3 In the last years, the use of contrast-enhanced MR cholangiography with Gd-EOB-DTPA has suggested to be effective in identifying such communications, ultimately allowing a confident, non-invasive diagnosis of CD.1 Nonetheless, the use of this technique in the diagnosis of CD has been very rarely reported in the literature.1,2 Although in our case late hepatobiliary phase images obtained 2h after contrast medium injection were sufficient, delayed images obtained after 24h1 may be necessary to demonstrate biliary-cysts communication in some cases of slow-filling cavities.
With this report we aim at emphasizing the role of modern hepatobiliary MR imaging with gadolinium based contrast agents as a noninvasive tool of demonstrating biliary-cysts communication, adding complementary diagnostic information to conventional MR sequences and allowing a conclusive diagnosis of CD in the appropriate clinical setting, without the use of invasive methods (e.g., endoscopic retrograde cholangiography and percutaneous transhepatic cholangiography), which may be associated with complications such as bleeding, infection and pancreatitis.4
Financial supportNone.
Conflicts of interestThe authors declare no conflict of interest.
