November 29, 2011 by dailybolusoflr
Imaging for Suspected Acute Cholecystitis
· The primary imaging modality of choice for acute cholecystitis is ultrasound.
· The presence of gallstones and a sonographic Murphy’s sign has a positive predictive value of about 92% for acute cholecystitis, with the sonographic Murphy’s sign being the most sensitive finding on ultrasound.
· Finding an impacted stone at the gallbladder neck also increases the likelihood of having acute cholecystitis in the right clinical setting.
· Other findings on ultrasound that can be seen in patients with cholecystitis are: pericholecystic fluid, a thickened gallbladder wall over 3mm, biliary sludge and a distended gallbladder
· CT is less sensitive for the detection of gallstones (about 75%) and is good for when complications of cholecystitis (abscess, progression to emphysematous cholecystitis) are suspected or when multiple other diagnoses are being considered.
· Hepatobiliary scintigraphy (HIDA scan) is useful when the diagnosis of acute cholecystitis is unclear. In patients with equivocal ultrasound but high clinical suspicion, this test can be useful to confirm the diagnosis.
Ref: Gastroenterol Clin N Am 39 (2010) 265–287