investigations

Last edited 02/2022

The investigations of choice in cholecystitis are:

  • FBC – usually shows leucocytosis
  • liver function test – to detect any obstructive jaundice (1)
  • abdominal x-ray:
    • can reveal radio-opaque stones in minority of cases
    • may show air in the biliary tree
    • can rule out intra-abdominal free air – seen in diverticulitis or perforated peptic ulcer (2)
  • ultrasound:
    • recommended for any suspected acute cholecystitis
    • first-choice imaging method for the morphological diagnosis of acute cholecystitis (3)
    • diagnosis of acute cholecystitis is made radiologically when the following are present at the same time:
      • thickening of the gallbladder wall (5 mm or greater)
      • pericholecystic fluid
      • ultrasonographic Murphy’s sign
        • pain which occurs when the probe is pushed against the gallbladder
        • superior to ordinary Murphy’s sign (3)
    • other findings may include: gallbladder enlargement, gallbladder stones, debris echo and gas imaging (3)
  • magnetic resonance cholangiopancreatography (MRCP):
    • can obtain images of the whole of the biliary tree and adjacent structures
    • small stones can be detected
    • recommended if abdominal ultrasound does not provide definitive diagnosis (3)
  • CT scan:
    • finding may include: gallbladder distention (41%), gallbladder wall thickening (59%), pericholecystic fat density (52%), pericholecystic fluid collection (31%) (3)
    • recommended for diagnosing gangrenous cholecystitis and emphysematous cholecystitis (3)
  • radio-isotopic scanning – HIDA scanning:
    • has a sensitivity of 80–90% for acute cholecystitis
    • normally outlines the gall bladder and duct system
    • if gallbladder is obstructed, cannot take up contrast, hence, not shown
    • ‘rim sign’ (a blush of increased pericholecystic radioactivity) is present in about 30% of patients with acute cholecystitis and in about 60% with acute gangrenous cholecystitis (3)
    • usually reserved for patients in whom diagnosis is unclear after ultrasonography (4)

Reference:

  1. Dawson J. Acute cholecystitis. GPonline 2009
  2. Elwood DR. Cholecystitis. Surg Clin North Am. 2008;88(6):1241-52
  3. Yokoe M, et al.Tokyo Guidelines 2018: diagnostic criteria and severity grading of acute cholecystitis (with videos). J Hepatobiliary Pancreat Sci. 2018 Jan;25(1):41-54. doi: 10.1002/jhbp.515. Epub 2018 Jan 9. PMID: 29032636.
  4. Strasberg SM. Clinical practice. Acute calculous cholecystitis. N Engl J Med. 2008;358(26):2804-11.