What can a gallbladder ejection fraction study show?
A gallbladder ejection fraction study can be performed in patients with a normally filling gallbladder who continue to have right upper quadrant symptoms. At the end of the standard hepatobiliary scan, CCK (or sometimes a fatty meal) is administered, and images are obtained for another 30 minutes. The radiotracer accumulation in the gallbladder on the pre-CCK and post-CCK scans can be compared to provide a gallbladder ejection fraction. A normal value is considered to be greater than 30% to 35%; however, the distribution of values in healthy individuals makes a normal range difficult to determine. If the ejection fraction is less than this value, gallbladder dysfunction is suspected. Cystic duct syndrome is considered if the gallbladder does not contract in a uniform manner or even expands after administration of CCK.