Cholecystokinin Test

Excerpt

Cholecystokinin (CCK), formerly referred to as pancreozymins, is another hormone-like secretin used in the pancreas's stimulation. Secretin mainly stimulates the secretion of pancreatic juice, which contains pancreatic enzymes and acts on the gallbladder, which can assess gallbladder function. CCK increases pancreatic enzyme output and causes gallbladder contraction. Therefore, the CCK test can help to diagnose biliary tract diseases.

Cholecystokinin-cholescintigraphy (CCK-HIDA) is the gold standard test for evaluating patients for obstructive cholecystitis or biliary dyskinesia. The finding of an abnormal gallbladder ejection fraction (GBEF) could signal the presence of an array of disease entities, including biliary dyskinesia, chronic or acute cholecystitis, bile sludging, etc. The HIDA may also demonstrate a filling defect, which represents a likely stone lodged in the cystic duct. Cholecystectomy is the recommended approach for those with abnormal GBEF and abdominal pain.

GBEF is calculated as the flow of radioactive tracer that is ejected from the gallbladder. A GBEF of <35% is considered abnormal. Patients considered for CCK-HIDA are those presenting with functional biliary pain based on the Rome III criteria. Those who present with atypical pain may not need as HIDA as the presentation may be from other pathology.