“Pneumobilia should be differentiated from portal venous gas. Portal venous gas is peripherally distributed to within 2 cm of the liver margin, whereas pneumobilia is centrally distributed.” (Gupta, P, et al. “PLAIN FILMS: BASICS.” Acute Care Surgery: Imaging Essentials for Rapid Diagnosis Eds. Kathryn L. Butler, et al. McGraw Hill, 2015.)

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• Air in the hepatic area:
  • Portal venous gas (liver periphery): ominous for intestinal necrosis or severe infection.
  • Pneumobilia (liver hilum): contact of intestinal lumen with biliary tree, eg, post-ERCP, gallstone ileus, hepaticojejunal anastomosis.

Further reading:

Soon WC, Liu KY, Blunt D. Hepatic portal venous gas. Clin Case Rep. 2015 Jun;3(6):518-9.

Shah PA, et al. Hepatic gas: widening spectrum of causes detected at CT and US in the interventional era. Radiographics. 2011 Sep-Oct;31(5):1403-13.

Nelson AL, et al. Hepatic portal venous gas: the ABCs of management. Arch Surg. 2009 Jun;144(6):575-81; discussion 581.

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