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.