What is a HIDA/DISIDA scan and why is it performed?

This scan is most commonly used to evaluate gallbladder function or obstruction of the cystic duct (acute cholecystitis). Other indications include evaluation of post-surgical complications e.g. bile leak and obstruction and even biliary atresia (congenital malformation of the bile ducts in neonates).

The scan is not useful to determine the presence of gallstones. Ultrasound of the liver and gallbladder is indicated to evaluate stones.

Patient preparation:

A person should be fasting for at least 4 – 6h hours prior to the scan. Most medication will not interfere with the study, but some type of pain killers may cause a problem and should sometimes be stopped 4 – 24h prior to the scan.

How does it work?

A small amount of a radiopharmaceutical is injected intravenously while you are positioned under the gamma camera. A dynamic phase (1h) is obtained as well as serial images up to 3h. If the gallbladder is not visualised at 1h, a fatty meal (normally an egg and bacon sandwich) is given with an additional set of images after 45 min.

In cases of biliary atresia delayed imaging at 24h may be necessary.