Diagnostic imaging of biliary obstruction

Determining whether an icteric patient has hepatic or posthepatic disease m ay be challenging. History, physical examination findings, and laboratory a nalyses do not allow the clinician to distinguish an icteric patient with b iliary obstruction that is in need of surgical intervention from one likely to respond to medical management. Survey radiography may provide informati on regarding size, shape, or opacity changes of the liver but is not sensit ive or specific for the diagnosis of biliary obstruction. Contrast radiogra phy is widely available and may provide evidence of obstruction but Is diff icult to perform successfully and may be associated with serious complicati ons. Ultrasonography is an available and sensitive tool for evaluation of b iliary tract distention. In many cases a specific cause for the distention is identifiable, but ultrasonographic examination may not distinguish betwe en current and previous biliary obstruction. Although limited in availabili ty, nuclear scintigraphy is a valuable tool in determining the patency of t he biliary tract. A combination of both clinical and imaging information is usually required to diagnose biliary tract obstruction.