Case:

88 year old female presented to ED with "chest pain" associated with nausea/vomiting x 2 days. VSS. On exam, she had RUQ tenderness to palpation. POCUS showed the following:

Case Explanation:

This ultrasound shows gallstones, pericholecystic fluid, and wall thickening consistent with acute cholecystitis. It also shows air bubbles within the lumen of the gallbladder (seen in the sagittal view). This has been previously described as an "effervescent gallbladder" (1). In transverse view, you can see a linear echogenic (bright white) focus along the anterior wall of the GB with posterior reverberation artifact (or "dirty shadowing"). These findings - air in the gallbladder lumen - are consistent with emphysematous cholecystitis.

The patient had a CT A/P which also showed a punctate focus of air within the gallbladder lumen. She subsequently went to the OR for a laparoscopic cholecystectomy.

Pearls:

Emphysematous cholecystitis is an anaerobic infection of the gallbladder that carries a mortality rate of 15-20% (compared to 1.4% for uncomplicated cholecystitis). The initial clinical picture is often the same as uncomplicated acute cholecystitis. It is associated with a high rate of gangrene and perforation and is a surgical emergency. Ultrasound is not highly sensitive for detecting emphysematous cholecystitis, but if air is visualized in the gallbladder this is a highly specific finding.

Adenomyomatosis of the GB (benign hyperplasia of the GB wall) can mimic emphysematous cholecystitis on US, but these patients are typically asymptomatic.

- Jessica Patterson, MD, Emergency Medicine Ultrasound Fellow

References

1. Oyedeji et al. Emphysematous Cholecystitis. Ultrasound Quarterly. 2014; 30(3); 246-248

2. Wu CS, Yao WJ, Hsiao CH. Effervescent gallbladder: sonographic findings in emphysematous cholecystitis. J Clin Ultrasound. 1998; 26: 272–275.

3. Sunnapwar et al. Emphysematous cholecystitis: Imaging findings in nine patients. Indian J Radiol Imaging. 2011 Apr-Jun; 21(2): 142–146.