"Supine radiographs often demonstrate a sword-shaped lucency in the right paraspinal region representing gas from the common duct and the left hepatic duct. This has been termed the sabre sign and is present in ~50% of patients with pneumobilia 4."
"Differentiating between biliary and portal venous gas is usually achievable especially when intravenous contrast is used. Gas within the biliary tree tends to be more central, whereas gas within the portal venous system tends to be peripheral (carried along by the blood). Also, biliary gas is anti-dependent, and typically fills the left lobe of the liver."
"ERCP"
"Whipple procedure"
"Doppler imaging may help"
"Pneumobilia, also known as aerobilia, is the accumulation of gas in the biliary tree. It is important to distinguish pneumobilia from portal venous gas, the other type of branching hepatic gas. There are many causes of pneumobilia and clinical context is often important to distinguish between these 3."
"patients usually ill (e.g. ischaemic bowel)"