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.

Inclusion Criteria:

- All patients referred to a HIDA scan for evaluation of gallbladder function.

- No evidence of gallbladder stones on any prior anatomic imaging studies.

- Patients who are able to lie flat on the imaging table for an additional 30 min. of
imaging after the standard of care 1.5 hour HIDA scan.

Exclusion Criteria:

- Patients who are under 18 years of age.

- Patients with evidence of gallbladder stones on other imaging modalities.

- Patient allergic to milk or dairy products.

- HIDA scan ordered to evaluate for acute cholecystitis.