What It Is
A HIDA scan is a nuclear medicine imaging test used to examine the function of the gallbladder and bile ducts, evaluating how well bile is flowing from the liver into the small intestine.
What It Checks
A HIDA scan uses a small amount of radioactive tracer that's taken up by the liver and then excreted into bile, allowing its movement to be tracked as it travels from the liver, into the gallbladder, and onward into the small intestine. This can reveal blockages or functional problems affecting this pathway that might not be clearly shown through other imaging methods.
Why It's Used
A HIDA scan is commonly used to investigate suspected gallbladder problems, particularly when there's a concern about whether the gallbladder is emptying and functioning normally, or when a blockage somewhere along the bile duct system is suspected.
How It's Done
Before a HIDA scan, a small amount of radioactive tracer is injected into a vein, and a special camera then tracks the tracer's movement over time as it passes from the liver into the bile ducts, gallbladder, and small intestine. The scan is typically taken in a series of images over the course of about an hour, sometimes longer if additional views are needed to fully assess gallbladder function.
Background
HIDA scanning developed as a specific nuclear medicine technique in the 1970s, building on broader advances in using radioactive tracers to study how organs function rather than simply their structure. It became a valuable tool for assessing bile duct and gallbladder function specifically, offering functional information that complements structural imaging methods like ultrasound, and it remains a useful, specialized test for gallbladder-related concerns today.