Gallbladder disease can include both anatomical and functional condition. We are familiar with gallstones. Bile acids, Lecithin (a phospholipid), and cholesterol are present in the Bile. When the proportional percentage of each one of them is outside a very narrow range, gallstones are formed. Approximately 75% of the gallstones are formed because of the supersaturation of the content of the gallbladder with cholesterol which results in cholesterol stone formation. The rest are pigmented stones.
Gallstones are usually identified by ultrasound and they are seen as shadows.
There are patients that have a normal gallbladder ultrasound result that continue to have signs and symptoms of gallbladder disease, such as abdominal pain in the right upper quadrant, nausea and vomiting with fatty meals, and bloating to name a few. These patients should be evaluated by a dynamic HIDA scan.
A dynamic HIDA scan study evaluates the function of the gallbladder, by creating a movie of the gallbladder, where as an ultrasound takes pictures of the gallbladder.
In a dynamic HIDA scan, and contractility of the gallbladder is reported in form of ejection fraction (%EF). This represent the amount of gallbladder contraction in response to the stimulation by a fatty meal mediated thru cholecystokinin (CCK). A normal EF is greater that 35%. Anything less than than with the sign and symptoms of gallstones, should be highly suspect for acalculous cholecystitis. Calculus because there is no stone.
(The bright white collection represents the filling of the gallbladder)
This short movie represents the uptake of the radio nuclear material in the gallbladder and its normal secretion in the small bowel.
These are the static images before the injection of CCK.
Following the injection, digital subsection of the images measure the amount of nuclear activity of the gallbladder before and after contraction and an Ejection Fraction is calculated.