Ultrasound Case 100

Image 1 and 2: Longitudinal and Transverse views of the gallbladder

There is gas in the gallbladder. The appearance of fine punctate, echogenic, non-shadowing foci, rising within the gallbladder like bubbles rising in champagne and has been termed the ‘effervescent’ gallbladder. These appear to arise from some sludge or small stones lying dependently and acting as the nidus for bubble formation. There is also a larger air bubble in the GB causing dirty posterior acoustic shadowing.

In addition the GB wall is thickened and oedematous with hypoechoic striations and some pericholecystic fluid. The patient was tender to probe pressure over the gallbladder.

This is acute cholecystitis and the presence of gas strongly supports the diagnosis of emphysematous cholecystitis.

Emphysematous cholecystitis

The effervescent gallbladder is a rare sign, but pathognomonic of gas in the gallbladder. It may be present because of acute cholecystitis and gas forming organisms. Clostridium welchii and Escherichia coli have been frequently implicated. Other possible causes include enterobiliary fistula formation – surgical or with gallstone perforation or tumour, incompetent sphincter of Oddi and drug effects (magnesium sulfate, atropine, nitroglycerin).

Gas and fluid in the bowel can create a very similar appearance and care should be taken to ensure the focus of the scan is definitely the gallbladder. Once again clinical correlation is paramount.

Rodríguez ÁL et al. “The Effervescent Gallbladder”: A Rare Ultrasonographic Finding that Reflects the Presence of Gas within the Gallbladder. Ultrasound Int Open. 2015; 1(2): 72-5