Jaundice

Jaundice refers to a clinical clinical sign of hyperbilirubinemia (>2.5 mg/dl) which has many causes. It is often a clue to a diagnosis. It can be largely divided into two types:

• obstructivenon-obstructive, i.e. pre-hepatic and hepatic causes
• non-obstructiveobstructive, i.e. post-hepatic causes

Imaging has a major role in detecting the obstructive causes.

Clinical presentation

Jaundice is the yellowing of the skin and/or sclera. Patients may present painless or painful jaundice. Painless jaundice is always very suspicious for an underlying obstructive malignant cause ³. 

Pathology

Categories of causes³:

• pre-hepatic (e.g. haemolytic)prehepatic
  • haemolytic anaemia
  • hepatic (within the liver)mechanical heart valve
  • post-hepatic (due to obstruction in biliary system)hypersplenism

  The biliary system can be divided into

• hepatic
  • intrahepatic system comprising of the hepatic ducts and its branchesacute hepatitis / acute liver failure
  • extrahepatic system comprising of common hepatic duct (CHD), common bile duct (CBD) and gallbladder (GB).cirrhosis
  • Gilbert syndrome 

  Obstruction at any extrahepatic site will lead to proximal dilatation.

  Common causes of obstruction

• post-hepatic (a.k.a. obstructive jaundice)
  • benign causes
    • post-inflammatory stricturechronic choledocholithiasis
    • strictures, e.g. post-inflammatory/infectious, primary sclerosing cholangitis
    • external biliary tree compression, e.g. pancreatic pseudocyst
    • , Mirizzi syndrome
  • malignant causes
    • portal lymphadenopathy
    • cholangiocarcinoma
    • carcinoma of head of pancreas
    • portal lymphadenpathy
    • hepatocellular carcinoma
    • gallbladder carcinoma

Radiographic features

Patients presenting with jaundice is a common indication for imaging. Often a specific cause will not be found, and the main role is differentiating between non-obstructive and obstructive jaundice. In the latter, extrahepatic and/or intrahepatic bile duct dilatation can be expected, depending on the level of obstruction. 

Hepatobiliary ultrasound and MRCP are the mainstay imaging modalities. Bilirubin levels are often too elevated for CT cholangiography to be performed.