Hepatic imaging often complements the findings of the patient’s history, physical examination, laboratory studies, and overall clinical presentation. Imaging studies are indicated to confirm the presence or the absence of biliary obstruction. Different accepted modalities to evaluate the biliary system include ultrasonography, CT scan of the abdomen, magnetic resonance cholangiopancreatography (MRCP), endoscopic ultrasonography, endoscopic retrograde cholangiopancreatography (ERCP), and percutaneous transhepatic cholangiography (PTC). Nuclear imaging of the biliary tree that measures hepatic uptake of radiolabeled derivatives of iminodiacetic acid (e.g., HIDA) is not sensitive enough to justify its use in the evaluation of jaundice.
Even if the clinical suspicion for biliary obstruction is thought to be low, evaluating liver parenchyma is as important as excluding that remote possibility of biliary obstruction. In that case, obtaining a CT scan or ultrasound of the abdomen might be an appropriate diagnostic tool. However, if dilated bile ducts are seen, direct imaging modalities such as MRCP, ERCP, or PTC should be obtained. Altogether, the sensitivity and specificity of these tests is 89%–100%.