• Complications: Liver abscesses, secondary biliary cirrhosis due to chronic infections, and cholangiocarcinoma
• Treatment: Combination of biliary drainage, stone retrieval, treatment of strictures, and antibiotics
Surgical resection of involved liver segments or liver transplant are also options
TERMINOLOGY
Abbreviations
• Recurrent pyogenic cholangitis (RPC)
Synonyms
• Oriental cholangitis, oriental cholangiohepatitis, intrahepatic pigment stone disease
• Biliary obstruction syndrome of Chinese/Hong Kong disease
Definitions
• Disease characterized by formation of pigment stones throughout biliary tree, with resultant biliary strictures and repeated bouts of cholangitis
IMAGING
General Features
• Best diagnostic clue
Intrahepatic and extrahepatic biliary dilatation with multiple biliary calculi
• Location
May be confined to left lobe (often lateral segment) or less commonly, right posterior segment
May involve all biliary ductal segments (and common bile duct) diffusely in later stages of disease
• Size
Stones typically 1-4 cm
• Morphology
Combination of pigment stones and biliary sludge
Fluoroscopic Findings
• ERCP
Dilated intrahepatic and extrahepatic bile ducts with disproportionate dilatation of extrahepatic duct
– Rapid tapering of dilated intrahepatic ducts with “arrowhead” configuration, ↓ arborization of peripheral ducts, and short segment bile duct strictures
Common duct and intrahepatic duct stones
Nonfilling of biliary ductal segments due to strictures of intrahepatic ducts (missing duct sign)
Vigorous injection of contrast during ERCP with overdistension of biliary tree may cause sepsis
CT Findings
• Dilatation of intrahepatic and extrahepatic biliary ducts
Disproportionate dilatation of extrahepatic and central intrahepatic bile ducts: CBD may be markedly enlarged
– ↓ arborization of peripheral ducts and multiple biliary strictures
– Preferential localized dilatation of bile ducts in left hepatic lobe and right posterior hepatic lobe
Ductal wall hyperenhancement and heterogeneous liver enhancement during acute cholangitis exacerbation
Pneumobilia (may not be related to prior intervention)
• Hepatolithiasis and choledocholithiasis
∼ 90% of stones are hyperdense to liver
Distribution of dilated ducts unrelated to location of calculi
• May be associated with pyogenic liver abscesses, bilomas, steatosis, segmental atrophy with chronic biliary obstruction, and cholangiocarcinoma
Atrophy most often affects left lateral segment of liver
– Atrophic segments may be steatotic with heterogeneous enhancement
Over time, scarring, atrophy, and capsular retraction of liver can produce cirrhotic morphology of liver
MR Findings
• Dilatation of intrahepatic and extrahepatic bile ducts, with disproportionate dilatation of extrahepatic and central intrahepatic ducts
MRCP nicely illustrates ↓ arborization of peripheral ducts, multiple intrahepatic biliary structures, and rapidly tapering intrahepatic ducts (arrowhead sign)
– Excellent sensitivity for detection of ductal dilatation, strictures, and calculi
– Strictures tend to encompass short segments (< 1 cm) and are easier to see on MRCP compared to CT
– Has ability to show ducts proximal to obstruction (advantage over ERCP)
Localized intrahepatic biliary ductal dilatation (± biliary stones) most commonly affects left liver lobe, and less commonly, posterior segment of right hepatic lobe
– May produce diffuse ductal dilatation in severe cases due to repeated bouts of inflammation
May be associated with thickening and hyperenhancement of bile duct walls on T1WI C+ images in setting of acute cholangitis
• Stones with low T2WI signal within both intrahepatic and extrahepatic ducts
Stones are primarily pigmented stones, and may be diffusely hyperintense or peripherally hyperintense (centrally hypointense) on T1WI
Sites of dilated bile ducts may not be closely related to the sites of bile duct stones
• Lobar or segmental liver parenchymal atrophy associated with sites of greatest biliary dilatation
Atrophic liver may be hypo-, iso-, or hyperintense on T1WI and mildly hyperintense on T2WI to normal liver
Ultrasonographic Findings
• Disproportionate dilatation of extrahepatic and central intrahepatic bile ducts
• Hepatolithiasis is seen in ∼ 90% of cases
Marked variability in echogenicity and acoustic shadowing of calculi
• Prominent periportal echogenicity
• Focal hypoechoic parenchymal lesions could represent liver abscess, biloma, or cholangiocarcinoma
Nuclear Medicine Findings
• WBC scan
Positive for cholangitic liver abscesses
Other Modality Findings
• Cholangiography
Similar to ERCP
Dilated intra- and extrahepatic ducts with filling defects (stones)
“Arrowhead” deformity of rapidly tapering intrahepatic ducts
Imaging Recommendations
• Best imaging tool
MRCP
• Protocol advice
DIFFERENTIAL DIAGNOSIS
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