3. Findings
Axial and coronal CT images show numerous round intrahepatic cystic lesions communicating with the
bile ducts.
Enhancing portal radicals are present within the cysts.
5. Differentials:
Primary sclerosing cholangitis: typically demonstrates isolated fusiform bile duct dilatation, rather
than saccular dilatation. Characterized by multiple intra- and extrahepatic strictures, caudate lobe
enlargement, and a lobulated liver contour. 70% of patients have inflammatory bowel disease.
Recurrent pyogenic cholangitis: typically demonstrates central fusiform bile duct dilatation with
peripheral tapering, rather than saccular dilatation. Hepatolithiasis is almost always present.
Polycystic liver disease: may present with both renal and hepatic cysts. Typically intra- and
extrahepatic bile ducts are normal, and hepatic cysts do not demonstrate ductal communication.
6. Discussion
Caroli disease is a rare autosomal recessive disorder resulting from abnormal intrahepatic bile ductal development. Two types have been
described: Caroli disease and Caroli syndrome (Caroli disease with hepatic fibrosis).
Caroli disease occurs following arrested ductal plate remodeling of the larger intrahepatic ducts. Typically manifests as saccular or fusiform
cystic intrahepatic ductal dilatation. Sludge or stones may develop within the dilated bile ducts. Irregular walls and strictures may be present.
On CT, these hypoattenuating lesions typically demonstrate central enhancing fibrovascular bundles within the cystic intrahepatic ducts
(“central dot sign”).
T2-weighted MR and MRCP show communication between the cystic dilatations and the bile ducts.
Complications in Caroli disease include cholangitis, liver abscess formation, bilirubin stone formation, cholangiocarcinoma, and obstruction.
In Caroli syndrome, cirrhosis and portal venous hypertension are often present at the time of presentation.
7. Management
In patients with disease that results in either repeated episodes of cholangitis or acquired biliary
cirrhosis, liver transplantation is preferable
10. Findings:
Ultrasound and MRCP show marked, saccular dilatation of the extrahepatic common bile duct
without an obstructing lesion and no evidence of intrahepatic bile ducts dilatation.
12. Differentials:
▶ Obstructed common bile duct: would not cause the profound and focal biliary dilatation seen in
the present case and there should be intrahepatic duct dilatation.
▶ Pancreatic pseudocyst: may mimic choledochal cyst on US and require additional imaging to
depict it as separate from the extrahepatic bile duct.
13. Discussion
Choledochal cyst is a nonhereditary congenital dilatation of the extrahepatic bile duct, which may have
intrahepatic duct involvement in the most severe cases. It is thought to be caused by reflux of pancreatic
secretions into the common bile duct because of an anomalous pancreaticobiliary junction.
The majority of patients with choledochal cysts are diagnosed in childhood and are female (4:1).
Five types of choledochal cysts have been described by Todani .
Imaging shows fusiform or saccular dilatation of the bile ducts.
Patients present with symptoms related to biliary stasis, such as RUQ pain, fever, and jaundice, and have a
15 percent risk for the development of cholangiocarcinoma, which may occur in young adulthood.
14. Management
Patients with a newly detected choledochal cyst should be recommended for gastroenterology
referral as a prelude to possible surgical resection given the risk of malignant degeneration.
This increased risk of cholangiocarcinoma remains after surgical treatment, particularly after
incomplete resection, indicating the need for lifelong surveillance
15. 42-year-old man with history of ulcerative colitis,
elevated liver function tests, and prior
instrumentation
16. Findings:
CT with intravenous contrast shows extensive periportal edema associated with pneumobilia, which is
a result of prior instrumentation.
The pneumobilia shows the caliber of the bile ducts is small to minimally dilated to the periphery of
the liver
18. Differentials:
▶ Recurrent pyogenic cholangitis: typically occurs in patients from Asia and is associated with
intrahepatic stones, usually with dilated bile ducts.
▶ Cholangiocarcinoma: bile duct dilatation almost always present in central tumors.
▶ Ascending cholangitis: usually has prior biliary disease or obstruction and generally not
associated with inflammatory bowel disease.
19. Discussion
Primary sclerosing cholangitis is a chronic progressive inflammatory disorder that is more common in middle aged
and is mostly associated with IBD.
The long-term sequelae of PSC are cirrhosis, portal hypertension, and ultimately liver failure.
Though ultrasound can reveal thickening of CBD wall with or without luminal obliteration.
At CT, beaded appearance of the biliary tract or mildly dilated discrete segments of intrahepatic ducts are seen
that may extend close to the liver periphery. Dilation of the extrahepatic biliary system is usually absent.
At MRCP, mild irregular intrahepatic ductal dilation with a beaded appearance without expected side branch
dilation, which is known as “pruning,” is often seen.
Sclerosing cholangitis predisposes patients to develop cholangiocarcinoma.
20. Management
Repeated mechanical balloon dilatation of affected bile ducts may be attempted at ERCP.
Imaging surveillance may be utilized to screen for cholangiocarcinoma.
22. Findings
T1-weighted MR image obtained during the portal venous phase shows mild intrahepatic bile duct
dilation.
MRCP image shows numerous intrahepatic bile duct strictures (short white arrows) with associated
mild bile duct dilation and a stricture at the ampullary portion of the distal common bile duct.
24. Differentials
▶ Primary sclerosing cholangitis: intra- and extrahepatic bile duct stricturing and dilation, often with
a beaded appearance. Papillary strictures are typically absent.
▶ Distal cholangiocarcinoma: may manifest as a distal common bile duct stricture. Associated
intrahepatic strictures are rare.
25. Discussion:
Opportunistic biliary tract infections by several organisms have been implicated in the development of AIDS- related
cholangitis but not directly demonstrated as causative. Direct involvement by the HIV virus has also been postulated as
an etiology.
US findings also include dilatation and mural thickening of the gallbladder and CBD as well as pericholecystic fluid.
Dilated intrahepatic ducts, GB dilatation and sludge are also commonly found.
On CT, inflammation of GB or bile ducts is manifest by wall thickening and/or abnormal contrast enhancement.
Direct cholangiography and MRCP are more sensitive and specific than CT and US in depicting the mural irregularity of
the extrahepatic ducts that result from exuberant periductal inflammation, mucosal ulcers, and interstitial edema of
AIDS-related cholangitis.
26. Management
AIDS cholangiopathy once carried a very grave prognosis. Highly active antiretroviral therapy has
made AIDS cholangiopathy uncommon.
Strictures can be managed with stenting. High serum alkaline phosphatase level is associated with a
worse outcome.
27. 53-year-old man with known primary sclerosing
cholangitis (PSC), complains of abdominal pain
and fevers.
28. Findings:
Two contiguous T1-weighted fat-saturated images following intravenous gadolinium demonstrate
multifocal areas of mild intrahepatic duct dilatation consistent with the patient’s known PSC.
In addition there is marked hyperenhancement of the wall of multiple intrahepatic ducts and mild
hyperemia in the surrounding liver parenchyma.
30. Differential:
Primary sclerosing cholangitis: this appearance can be seen in uncomplicated PSC, and the diagnosis
of acute cholangitis is based on the clinical and laboratory findings.
32. Findings
T1-weighted MR obtained in the portal venous phase shows an ill-defined hypovascular infiltrative
mass arising near the confluence of the main right and left bile ducts, causing moderate intrahepatic
bile duct dilatation.
MRCP shows dilated intrahepatic bile ducts and a normal distal common bile duct and pancreatic
duct, confirming the level of obstruction at the level of the hepatic hilum.
ERCP obtained during stent placement demonstrates moderate intrahepatic dilatation and a normal-
caliber common bile duct.
34. Differentials
▶ Pancreatic carcinoma: arises from ductal epithelium of the exocrine pancreas, causes abrupt
obstruction and dilatation of the main pancreatic duct and distal CBD, and can infiltrate the
peripancreatic fat.
▶ Primary sclerosing cholangitis (PSC): mild dilatation of both intra- and extrahepatic bile ducts,
with isolated obstruction of segmental intrahepatic bile ducts. ERCP images show irregular biliary
strictures,
beading and pruning.
▶ Other porta hepatis tumor: hepatocellular carcinoma, lymphoma, and hilar liver metastasis (breast
or gastrointestinal cancers) may invade and obstruct the central intrahepatic bile ducts.
35. Discussion
Cholangiocarcinoma is an adenocarcinoma that arises from bile duct epithelium. It is usually classified
as either intrahepatic (peripheral) or extrahepatic.
When the malignancy arises from one of the hepatic ducts or the bifurcation of the common hepatic
duct, it is called hilar cholangiocarcinoma (Klatskin tumor).
The most typical presentation of hilar cholangiocarcinoma is as a periductal infiltrating mass. About
80 percent of these tumors are hyperattenuating relative to the liver on delayed contrast-enhanced
images due to abundant fibrous tissue. Mass-forming and polypoid hilar cholangiocarcinomas are less
common.
36. Management
Surgical resection including major hepatic resection remains the mainstay of treatment of hilar
cholangiocarcinoma.
Surgical exploration should only be performed when preoperative examination has shown curative
resection to be possible.
