A 52 y.o. presents with fever; he is developmentally delayed and cannot give a history.

What do you notice on the abdominal CT?.

Our patient had pneumobilia. This can be a benign condition or it may be a serious condition.  In the case of our patient he had a bile duct injury in the past and underwent a bepatico-duodenostomy which explains the air in the biliary tree. Other common conditions associated with pneumobilia include: an incompetent sphincter of Oddi or a spontaneous biliary enteric fistula. Serious conditions include gas forming organisms or an emphysematous gall bladder.

gallstone pancreatitis causes a biliary enteric fistula

Pneumobilia is to be distinguished from gas in the portal venous system. This can indicate  severe abdominal pathology requiring urgent operative intervention as in cases of ischemic bowel. . Gas in the portal venous system was first described by Wolfe  in infants with necrotizing enterocolitis. Portal venous gas tends to flow to the periphery of the liver( within 2 cm of the liver edge)  while biliary gas is more central.

portal venous gas is more peripheral

Our patient was admitted with fever and found to have pneumonia. He was successfully treated and discharged. Incidentally, large a large amount of stool was seen in the colon compatible with his known chronic constipation.

Sherman SC, Tran J.  Pneumobilia: benign or life-threatening. J Emerg Med 2006 Feb;30(2):147-53.

Marshall SF, Polk RC. Spontaneous internal biliary fistula .Surg Clin Normth AM 1958;38:679.

Abboud B, Hachem J, Yazbeck T Doumit C. Hepatic portal venous gas: Physiopathyology, etiology, prognosis and treatment. World J Gastroenterol. 2009 Aug 7;15(29): 3585-3590.