Which test is used to assess the functionality of the gallbladder?

The HIDA scan, also known as hepatobiliary Iminodiacetic Acid scan, is the most effective test for assessing the functionality of the gallbladder. This nuclear medicine imaging technique involves injecting a radioactive tracer that is taken up by the liver and excreted into the bile. If the gallbladder is functioning properly, it will concentrate the tracer and show up on the scan. This allows clinicians to evaluate not only whether the gallbladder can take up the tracer but also whether it can excrete it into the duodenum, providing insight into gallbladder motility and function.

Other imaging modalities, like ultrasound and CT scans, are excellent for visualizing gallstones or anatomical abnormalities, but they do not provide quantitative data regarding gallbladder function. Meanwhile, MRCP is particularly useful for imaging the biliary tree and assessing for strictures or stones within the bile ducts, but it does not offer direct assessment of gallbladder contractions or emptying capabilities. This makes the HIDA scan the gold standard for understanding gallbladder function specifically.