Which finding suggests biliary tract obstruction on imaging and labs?

Which finding suggests biliary tract obstruction on imaging and labs?

• A. CBD dilation with elevated bilirubin
• B. CBD dilation with normal bilirubin
• C. Elevated bilirubin with normal CBD
• D. No CBD dilation with elevated bilirubin

Answer: (A)

Obstructive jaundice causes dilation of the biliary tree on imaging and a cholestatic pattern on labs. When the common bile duct is dilated and bilirubin is elevated, it points to a blockage somewhere in the biliary tract preventing bile from reaching the intestine. Bile components back up into the bloodstream, raising direct (conjugated) bilirubin and typically alkaline phosphatase as well. This combination—a dilated common bile duct with elevated bilirubin—is the classic clue that there is an obstruction in the biliary system, such as a stone in the CBD or a stricture. If the CBD were dilated but bilirubin remained normal, or if bilirubin were elevated without CBD dilation, other processes (partial/early obstruction, hepatocellular injury, or intrahepatic cholestasis) would be more likely.

Obstructive jaundice causes dilation of the biliary tree on imaging and a cholestatic pattern on labs. When the common bile duct is dilated and bilirubin is elevated, it points to a blockage somewhere in the biliary tract preventing bile from reaching the intestine. Bile components back up into the bloodstream, raising direct (conjugated) bilirubin and typically alkaline phosphatase as well. This combination—a dilated common bile duct with elevated bilirubin—is the classic clue that there is an obstruction in the biliary system, such as a stone in the CBD or a stricture. If the CBD were dilated but bilirubin remained normal, or if bilirubin were elevated without CBD dilation, other processes (partial/early obstruction, hepatocellular injury, or intrahepatic cholestasis) would be more likely.