Diagnostic Workup for Cholecystitis

Clinical Evaluation

The American College of Emergency Physicians recommends that the diagnostic workup for cholecystitis should include a combination of detailed history, physical examination, laboratory tests, and imaging studies, with abdominal ultrasound being the first-line imaging modality due to its wide availability, lack of radiation exposure, and good diagnostic accuracy 1, 2
Key features of the history include right upper quadrant pain, fever, nausea, vomiting, and food intolerance 1, 3
Physical examination should look for right upper quadrant tenderness and Murphy's sign (pain on inspiration during palpation of the right upper quadrant) 1, 4
No single clinical or laboratory finding has sufficient diagnostic power to establish or exclude cholecystitis 4

Complete blood count may show elevated white blood cell count, which is common in patients with cholecystitis 1
C-reactive protein elevation suggests inflammation 1, 4
Liver function tests may be elevated but are not specific for cholecystitis; they are helpful to assess for potential common bile duct stones 5

Abdominal ultrasound should be performed first in all patients with suspected cholecystitis, with a sensitivity of 81% and specificity of 83% 2, 5, 6, 7
Ultrasound findings to look for include gallstones, gallbladder wall thickening, pericholecystic fluid, and sonographic Murphy's sign 5, 7
The American College of Radiology recommends hepatobiliary iminodiacetic acid (HIDA) scan as the second-line imaging test for equivocal cases, with the highest sensitivity (97%) and specificity (90%) for cholecystitis 2, 5
MRI may be considered in patients with equivocal ultrasound findings or to better visualize hepatic and biliary abnormalities, with similar accuracy to ultrasound but higher cost 2, 8
CT scan has a limited role in primary diagnosis of cholecystitis but may be useful for evaluating complications or for surgical planning 2, 8

Initial assessment should include history, physical examination, and laboratory tests 1, 4
First-line imaging should be abdominal ultrasound 2, 7
If ultrasound is inconclusive, HIDA scan is the preferred second-line test, or alternative MRI if available 2, 5, 8
If complications are suspected, consider CT scan 8