Final answer:
A hepatobiliary iminodiacetic acid (HIDA) scan, also known as cholescintigraphy, is a nuclear imaging procedure to assess gallbladder and bile ducts function by tracking the movement of a radioactive tracer that mimics bile flow. The images captured can help diagnose conditions like blockages or dysfunctions in the hepatobiliary system.
Step-by-step explanation:
A hepatobiliary iminodiacetic acid (HIDA) scan, also known as cholescintigraphy, is a medical imaging procedure used to evaluate the function of the gallbladder and bile ducts. In this test, a radioactive tracer substance, usually hydroxy iminodiacetic acid (HIDA), is injected into a vein in the arm. The liver processes the tracer, which then flows through the bile ducts and into the gallbladder, mimicking the flow of bile.
The gallbladder's role is to store this bile fluid, then release it into the small intestine to aid digestion, particularly fats, and to neutralize stomach acid. The HIDA scan monitors the movement of the radioactive tracer from the bloodstream to the liver, through the bile ducts, and into the gallbladder and the beginning of the small intestine. A specialized gamma camera captures images of this process, allowing doctors to detect issues such as blockages or gallbladder dysfunction.
Compared to other diagnostic tests like abdominal X-rays, Computed tomography (CT) scans, Magnetic resonance cholangiopancreatography (MRCP), or Endoscopic retrograde cholangiopancreatography (ERCP), the HIDA scan provides a dynamic view of the bile's movement through the hepatobiliary system. This scan is particularly helpful for diagnosing conditions like acute cholecystitis or biliary atresia, where gallbladder function is impaired.