False-negative morphine-augmented hepatobiliary scintigraphy with a rim sign

Area of Science:

• Hepatobiliary imaging
• Diagnostic nuclear medicine
• Gastrointestinal diagnostics

Background:

• Hepatobiliary scintigraphy (HBS) is crucial for diagnosing gallbladder disease.
• Acute cholecystitis is often suspected based on clinical presentation and imaging findings.
• Morphine administration is used in HBS to stimulate gallbladder contraction or visualize the cystic duct.

Observation:

• A patient with gallstones and suspected acute cholecystitis showed initial nonvisualization of the gallbladder on HBS.
• A subtle "rim sign" was noted on initial imaging.
• Delayed gallbladder visualization occurred after intravenous morphine administration.

Findings:

• Subsequent cholecystectomy revealed a gangrenous gallbladder with a gallstone and full-thickness necrosis.
• The "rim sign" in conjunction with delayed visualization post-morphine did not rule out severe acute cholecystitis.
• Histopathology confirmed gangrenous cholecystitis, indicating a severe inflammatory process.

Implications:

• Gallbladder visualization on morphine-augmented HBS, especially with a "rim sign," should be interpreted cautiously.
• Acute cholecystitis may still be present despite delayed visualization after morphine.
• This case highlights the importance of correlating imaging findings with clinical suspicion in diagnosing acute cholecystitis.