Poor contraction of the gallbladder results in biliary stasis and may favor gallstone formation. The gallbladder ejection fraction measures the ability of the gallbladder to empty following a stimulus.


Initially the gallbladder is assessed in the fasting state. Afterwards, the gallbladder is induced to contract. Methods to achieve gallbladder contraction:

(1) fatty meal

(2) infusion of cholecystokinin


After the contraction is initiated, measurements may be taken at set times. Some protocols use measurements at 30, 60 and 90 minutes after the stimulus. Others can be completed within 30 minutes.


Scintigraphic Method


Commonly used radionuclide for cholescintigraphy: Technetium-99m HIDA


reading =

= (counts with source material) – (background counts)


ejection fraction in percent =

= 100% * ((gallbladder reading before evacuation) – (gallbladder reading after evacuation)) / (gallbladder reading before evacuation)




volume of the gallbladder in cubic cm =

= π/6 * (length in cm) * (lateral diameter in cm) * (anterior-posterior diameter in cm)


ejection fraction in percent =

= 100% * ((gallbladder fasting volume) – (gallbladder residual volume)) / (gallbladder fasting volume)


ejection volume in cubic cm =

= (fasting volume in cc) – (residual volume in cc)


This method may experience problems when the gallbladder deviates from the idealized shape due to scarring or other causes.




Impaired biliary emptying may be associated with increased fasting volumes and low ejection fraction.


Criteria for poor contraction:

(1) ejection fraction of 20-40%

(2) ejection volume < 50% of prefasting volume


To read more or access our algorithms and calculators, please log in or register.