Emphysematous Cholecystitis

Fig. 1: Transverse ultrasound image (with color flow) of an 82-year-old woman with RUQ pain shows thickening of the gallbladder wall (two-head arrow), distended gallbladder, and multiple hyperechoic dots with posterior reverberation artifacts (or 'ring-down' artifacts).
Fig. 2: Coronal-reformatted CT image performed subsequently reveals gas (arrow) in the gallbladder lumen, marked thickening of the gallbladder wall (double-head arrow), distention of gallbladder, enhancement of gallbladder wall (arrowheads). Conglomerate mass in the gallbladder wall represents sludge. Findings are consistent with emphysematous cholecystitis.

Facts

• Gas in gallbladder wall or lumen
• Clinical setting of acute cholecystitis
• No evidence of fistula between gallbladder and bowel
• Common organisms are Clostridium, E. coli, S. aureus and Streptococcus.

Imaging

• May be seen on radiography as curvilinear lucency or air-fluid level in RUQ
• Gas on ultrasound appears as hyperechoic dots/line with posterior reverberation artifact
• CT is the most specific and sensitive method to diagnose this condition.

Reference:
Smith EA, et al. Cross-sectional imaging of acute and chronic gallbladder inflammatory disease. AJR 2009; 192:188-196