Evaluation of Gallbladder Contractility Using Both CCK and Milk Consecutively

Hepatobiliary imaging (HIDA) has an important role in the evaluation of the function and dynamics of the hepatobiliary system and the flow of bile to the gastrointestinal system. Contractility of the gallbladder is one of the functions that are uniquely evaluated using a HIDA scan. Poor contractility of the gallbladder can be the source of pain in many patients. Anatomic imaging studies like ultrasound, CT and/or MRI are usually normal in these patients.

Contractility of the gallbladder is evaluated during a HIDA scan by intravenous injection of cholecystokinin (CCK) a physiologic peptide enzyme produced in the duodenum in response to the presence of fatty meal which causes the gallbladder to contract and the sphincter of Oddi to relax, thus allowing the flow of bile from the gallbladder to the duodenum. CCK is usually administered during a HIDA scan intravenously after filling of the gallbladder with radioactive tracer to simulate the action of the endogenous CCK in contracting the gallbladder and relaxation of the sphincter of Oddi. Gallbladder ejection fraction (GBEF) in response to CCK injection is calculated using special computer software program. A normal gallbladder ejection fraction is equal to or greater than 35%. Alternative to CCK injection, the patient may be administered milk as a fatty drink that should stimulate a normal gallbladder to contract when it reaches the duodenum approximately 15-20 minutes after oral administration. Thus, gallbladder contractility may be evaluated during a HIDA scan either by injecting CCK intravenously or oral administration of milk. Poor contractility of the gallbladder may result in abdominal pain usually triggered by meals. However, in many patients with abdominal pain and a decreased gallbladder contractility as evaluated by IV CCK or milk may continue to suffer from pain even after surgical removal of the gallbladder . This suggests that abnormally decreased GBEF after CCK or milk stimulation may represent false abnormal finding resulting in unnecessary cholecystectomies in some of the patients. There are no reports in the literature that have used both intravenous CCK stimulation and oral milk administration together in the same patient.

This study aims to combine the use of IV CCK administration followed by oral milk during a HIDA scan to further stimulate the gallbladder contractility and decrease the number of false abnormal HIDA scans and unnecessary cholecystectomies in some patients.