Acute Cholecystitis

Coronal CT images show dilated gallbladder (GB), thickened wall, mucosal hyperenhancement with an obstructing cystic duct stone (arrow) in a 57-year-old man who presents with acute abdominal pain.

Facts: Acute Cholecystitis

• It is a difficult clinical diagnosis. Potential clinical signs that can be helpful to rule in the diagnosis are 1) Murphy sign (positive likelihood ratio = 2.8), 2) RUQ tenderness
• Diagnosis requires a combination of clinical, lab and imaging tests.
• No single clinical finding or lab test has sufficient weight to establish or exclude cholecystitis without further testing (eg, imaging)
• Evaluation of patients with abdominal pain suggestive of cholecystitis continues to rely heavily on the clinical gestalt and diagnostic imaging

Facts: Acute Cholecystitis CT Findings

• Gallbladder distention*
• Wall thickening*
• Mucosal hyperenhancement
• Pericholecystic fat stranding or fluid
• Gallstones (with sufficient attenuation difference from bile to be visualized)
• CT rim sign (increased enhancement of hepatic parenchyma in the gallbladder fossa)
• CT is less accurate than ultrasound in establishing or excluding cholecystitis. However, CT is better to show complications of cholecystitis such as emphysema, gangrene, perforation, abscess or hemorrhage.

* In one study (ref #3), distended gallbladder was considered when size greater than 5 x 8 cm, and thickened wall when greater than 4 mm in noncollapsed gallbladder (short axis greater than 2 cm).

References:

1. Trowbridge RL, Rutkowski NK, Shojania KG. Does this patient have acute cholecystitis? JAMA 2003;289:80-86.

2. Shakespear JS, Shaaban AM, Rezvani M. CT findings of acute cholecystitis and its complications. AJR 2010;194:1523-1529.

3. Fidler J, Paulson EK, Layfield L. CT evaluation of acute cholecystitis: findings and usefulness in diagnosis. AJR 1996;166:1085-1088.