CCKcholescintigraphy

CCK-cholescintigraphy, also known as cholecystokinin cholescintigraphy, is a nuclear medicine test that uses a radiotracer to evaluate biliary tract function, particularly gallbladder emptying. The procedure typically employs technetium-99m labeled bile analogs (such as mebrofenin or disofenin). After intravenous injection of the radiotracer, dynamic imaging is performed to visualize hepatic uptake, biliary excretion, and gallbladder filling. Cholecystokinin (or its analog sincalide) is then administered to provoke gallbladder contraction. Additional imaging measures the radiotracer ejected from the gallbladder, yielding a gallbladder ejection fraction (GBEF).

Interpretation centers on gallbladder visualization and ejection. Non-visualization of the gallbladder on baseline imaging or persistent non-visualization after CCK suggests acute cholecystitis or biliary obstruction. A reduced GBEF indicates gallbladder dysfunction, such as biliary dyskinesia or chronic cholecystitis. Normal GBEF values are generally in the mid-to-high thirties to fifties percent, though thresholds vary by protocol. Delayed filling or altered transit can also be informative.

Indications include evaluation of suspected acute cholecystitis when ultrasound is inconclusive, assessment of biliary colic due to functional gallbladder disorders, and selective functional assessment of biliary emptying for surgical planning. The test complements anatomy-focused imaging.

Limitations include dependence on fasting state, hepatocellular disease, recent meals, and medications affecting bile flow. Radiation exposure is low but present; safety considerations apply in pregnancy and lactation. Cholescintigraphy with CCK is a functional adjunct to ultrasound and other imaging in biliary disease.