Acute cholecystitis

Dr Henry Knipe and Radswiki et al.

Acute cholecystitis refers to the acute inflammation of the gallbladder. It is the primary complication of cholelithiasis and the most common cause of acute pain in the right upper quadrant (RUQ).

Constant right upper quadrant pain that can radiate to the right shoulder. Cholecystitis pain typically persists for more than six hours compared to the intermittent right upper quadrant pain of biliary colic. Nausea, vomiting, and fevers are also often reported.

Approximately 90-95% of cases are due to gallstones. The development of acute calculous cholecystitis follows a sequence of events:

  1. gallstone obstruction of the gallbladder neck or cystic duct
  2. inflammation from chemical injury of the mucosa by bile salts
  3. reactive production of mucus, leading to increased intraluminal pressure and distention
  4. increased luminal distention restricting blood flow to the gallbladder wall (gallbladder hydrops)
  5. increasing wall thickness from edema and inflammatory changes
  6. secondary bacterial infection in ~66% of patients

Ultrasound (US) is the preferred initial modality in the investigation of right upper quadrant pain. It is more sensitive than HIDA scintigraphy 4 and CT in the diagnosis of acute cholecystitis, and more readily available.


The most sensitive US finding in acute cholecystitis is the presence of cholelithiasis in combination with the sonographic Murphy sign. Both gallbladder wall thickening (>3 mm) and pericholecystic fluid are secondary findings. 

Other less specific findings include gallbladder distension and sludge.

Every effort should be made to demonstrate the obstructing stone in the gallbladder neck or cystic duct.

Nuclear medicine
99mTc-HIDA scintigraphy

HIDA cholescintigraphy in acute cholecystitis will demonstrate nonvisualization of the gallbladder.  

Cholescintigraphy is unable to demonstrate many complications of cholecysitis, nor the alternative diagnoses which may be found with US. It is therefore reserved for the evaluation of sonographically equivocal cases.


Although less sensitive than ultrasound, CT findings include 3:

  • cholelithiasis
  • gallbladder distension
  • gallbladder wall thickening
  • mural or mucosal hyperenhancement
  • pericholecystic fluid and inflammatory fat stranding
  • enhancement of the adjacent liver parenchyma due to reactive hyperaemia
  • tensile gallbladder fundus sign 7
    • fundus bulging the anterior abdominal wall
    • ~75% sensitivity and ~95% specificity for acute cholecystitis in the absence of any other CT features
    • useful sign in making early diagnosis

Diagnostic criteria on CT as proposed by Mirvis et al. include 6:

  • major criteria
    • gallstones
    • thickened gallbladder wall
    • pericholecystic fluid collections
    • subserosal edema.
  • minor criteria
    • gallbladder distention
    • sludge
  • diagnosis of acute cholecystitis can be supported if 1 major and 2 minor criteria are present refs

MRI is sensitive in the detection of acute cholecystitis, with findings similar to those seen on ultrasound and CT 3. MR cholangiopancreatography (MRCP) may show  an impacted stone in the gallbladder neck or cystic duct.

Urgent surgical removal of the gallbladder is the treatment of choice for uncomplicated disease. Gallbladder ischemia and transmural necrosis may occur if the obstruction persists.


Differential diagnosis for acute cholecystitis is extensive and includes:

For a more extensive differential, please refer to the article on differential diagnosis of diffuse gallbladder wall thickening.

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Article Information

rID: 12084
Section: Pathology
Synonyms or Alternate Spellings:
  • Cholecystitis - acute

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    Case 4: with cystic duct obstruction
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    Case 5: calculus cholecystitis - ultrasound
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    Case 7: complicated with pericholecystic abscess
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    Case 8: complicated with hepatic abscess 
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    Case 10: with tensile gallbladder fundus sign
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