Cholecystokinin cholescintigraphy: clinical indications and proper methodology

Cholecystokinin is a useful diagnostic adjunct to cholescintigraphy. Clinical indications include contracting the gallbladder before cholescintigraphy in patients fasting greater than 24 hours, during cholescintigraphy to diagnose sphincter of Oddi dysfunction, and after cholescintigraphy to exclude acute acalculous cholecystitis, differentiate common duct obstruction from normal variation, and to confirm the diagnosis of chronic acalculous cholecystitis. Proper methodology is mandatory for a diagnostically useful test. Data presented shows that a 3-minute infusion of 0.01 or 0.02 microg/kg is nonphysiologic and often results in ineffective contraction similar to that seen with a bolus infusion. Normal gallbladder ejection (GBEF) values cannot be established using a 3-minute infusion because of the wide variability in response. Instead, infusions of 30 or 60 minutes are required. Normal GBEF values have been established for these methods and are 30% and 40%, respectively.