Pneumobilia Diagnosis and Management

Clinical Significance

Pneumobilia indicates an abnormal communication between the biliary tract and the gastrointestinal system, or less commonly, infection by gas-forming bacteria, and requires immediate investigation to determine if surgical intervention is needed 1, 2
The American College of Emergency Physicians suggests that pneumobilia can lead to serious complications, including cholangitis and bacteremia, even after prolonged asymptomatic periods, although the strength of this evidence is not specified 1

On ultrasound, pneumobilia produces increased echogenicity with comet-tail artifact caused by gas in the biliary tree, which can be subtle and easily overlooked 1
Pneumobilia may be confused with adjacent bowel gas on ultrasound; optimization of gain settings and scanning from multiple directions is essential 1
The finding is subtle and can produce comet-tailing similar to cholesterol stones, requiring careful evaluation 1