In patients with suspected gallbladder disease, ultrasound is the first-line imaging modality and should be interpreted by identifying key features such as gallstones, gallbladder wall thickening, pericholecystic fluid, and bile duct dilation. The presence of gallstones within the gallbladder on ultrasound confirms gallstone disease, especially when correlated with symptoms, and supports a diagnosis of symptomatic gallbladder stones if clinical features are present. A normal gallbladder with asymptomatic stones generally does not require treatment NICE CG188.
Gallbladder wall thickening (>3 mm), pericholecystic fluid, and a sonographic Murphy’s sign (maximal tenderness over the gallbladder during scanning) are suggestive of acute cholecystitis. Early laparoscopic cholecystectomy is recommended within one week of diagnosis in such cases NICE CG188.
If the common bile duct is dilated on ultrasound or liver function tests are abnormal, further imaging with magnetic resonance cholangiopancreatography (MRCP) should be considered to detect common bile duct stones, as ultrasound may miss these stones NICE CG188. Endoscopic ultrasound (EUS) is reserved for cases where MRCP is inconclusive NICE CG188.
Ultrasound interpretation should also consider potential pitfalls such as mistaking sludge for stones or confusing gallbladder wall thickening due to other causes (e.g., hepatitis, heart failure) with cholecystitis. Recent literature emphasizes the importance of correlating ultrasound findings with clinical presentation and laboratory results to improve diagnostic accuracy Klimkowski et al. 2022.
Advanced imaging techniques, including dual-energy CT and multimodality imaging, can complement ultrasound in complex cases but are not first-line investigations Ratanaprasatporn et al. 2018. The Infectious Diseases Society of America also highlights ultrasound as the primary diagnostic tool for acute cholecystitis and cholangitis, reinforcing its role in initial assessment Bonomo et al. 2024.
Key References
- CG188 - Gallstone disease: diagnosis and management
- NG126 - Ectopic pregnancy and miscarriage: diagnosis and initial management
- NG224 - Urinary tract infection in under 16s: diagnosis and management
- (Ratanaprasatporn et al., 2018): Multimodality Imaging, including Dual-Energy CT, in the Evaluation of Gallbladder Disease.
- (Klimkowski et al., 2022): Gallbladder Imaging Interpretation Pearls and Pitfalls: Ultrasound, Computed Tomography, and Magnetic Resonance Imaging.
- (Bonomo et al., 2024): 2024 Clinical Practice Guideline Update by the Infectious Diseases Society of America on Complicated Intraabdominal Infections: Diagnostic Imaging of Suspected Acute Cholecystitis and Acute Cholangitis in Adults, Children, and Pregnant People.