Portal venous gas

  • Always abnormal
  • Present when intestinal permeability increases or when there is increase in intestinal luminal pressure
  • Neonatal necrotising enterocolitis, adults with gastric emphysema, intestinal obstruction, infection, Crohn disease
  • Blunt abdominal trauma, invasive malignancies (colon, ovarian carcinoma)
  • Duodenal perforation at ERCP
  • Colitis following barium enema
  • Gas radiates out of hilum
  • Less gravity dependence than pneumobilia, more peripheral distribution
  • US: moving gas bubbles in portal vein. Aliasing artifacts on spectral display. 
  • CT and radiograph: evident when enough gas accumulates and is seen in periphery of liver 
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Faberman, Robert S., and William W. Mayo-Smith. “Outcome of 17 patients with portal venous gas detected by CT.” AJR. American journal of roentgenology 169.6 (1997): 1535-1538.

Sisk, Phillip B. “Gas in the portal venous system.” Radiology 77.1 (1961): 103-107.

Liebman, PAUL R., et al. “Hepatic–portal venous gas in adults: etiology, pathophysiology and clinical significance.” Annals of surgery 187.3 (1978): 281.