What is a Hepatobiliary Iminodiacetic Acid (HIDA) scan?

From the Guidelines

A HIDA scan is a highly sensitive and specific medical imaging test used to diagnose acute calculus cholecystitis (ACC) and other hepatobiliary disorders. According to the 2020 World Society of Emergency Surgery guidelines 1, the HIDA scan has the highest sensitivity and specificity for diagnosing ACC compared to other imaging modalities. This test involves injecting a radioactive tracer into the bloodstream, which is then taken up by liver cells and excreted into bile, allowing doctors to track bile flow through the biliary system.

The HIDA scan is particularly useful for evaluating the function of the gallbladder and bile ducts, and can help diagnose conditions such as gallbladder inflammation, bile duct blockages, and bile leaks. The diagnostic accuracy of computed tomography (CT) is poor, while magnetic resonance imaging (MRI) is as accurate as abdominal ultrasound 1.

Some key points to consider when using a HIDA scan include:

• The test is generally safe with minimal radiation exposure
• Patients may need to fast for 4-6 hours before the procedure
• A medication called cholecystokinin (CCK) may be given to stimulate gallbladder contraction
• The test provides valuable functional information that other imaging tests like ultrasound cannot, helping doctors determine the appropriate treatment for biliary system disorders.

Overall, the HIDA scan is a valuable diagnostic tool for evaluating hepatobiliary disorders, and its high sensitivity and specificity make it a recommended test for diagnosing ACC and other conditions 1.

From the FDA Drug Label

Following intravenous administration in normal subjects, Technetium Tc 99m Mebrofenin was rapidly cleared from the circulation... The injected activity was cleared through the hepatobiliary system with visualization of the liver by 5 minutes and maximum liver uptake occurring at 11 minutes post-injection. A Hepatobiliary Iminodiacetic Acid (HIDA) scan is an imaging test that uses a radioactive tracer, such as Technetium Tc 99m Mebrofenin, to visualize the liver, gallbladder, and bile ducts. The scan is used to assess hepatobiliary function and diagnose certain conditions, such as gallbladder disease or bile duct obstruction. Key points about the scan include:

• The tracer is rapidly cleared from the circulation and taken up by the liver
• The liver is visualized within 5 minutes of injection
• The gallbladder and bile ducts are visualized within 10-15 minutes of injection
• The scan can be used to diagnose conditions such as gallbladder disease, bile duct obstruction, and hepatocellular disease 2

From the Research

Definition and Purpose of HIDA Scan

• A Hepatobiliary Iminodiacetic Acid (HIDA) scan is a nuclear medicine test that uses a small amount of radioactive material to evaluate the function and structure of the biliary system, including the gallbladder, bile ducts, and liver 3, 4, 5.
• The test involves injecting a radioactive tracer, usually technetium-99m (99mTc), into a vein, which is then taken up by the liver and excreted into the bile ducts and gallbladder 3, 4.

How the HIDA Scan Works

• The 99mTc-HIDA tracer is concentrated by the hepatocytes and excreted into the biliary system, allowing for visualization of the gallbladder, common bile duct, and duodenum within 30 minutes of intravenous administration 3.
• The scan can be used to diagnose various biliary disorders, including acute and chronic cholecystitis, biliary obstruction, and hepatocellular disease 3, 4, 6.

Clinical Applications of HIDA Scan

• The HIDA scan is useful in assessing biliary drainage in jaundiced patients with surgically altered biliary tract anatomy 3.
• It can also be used to evaluate patients with typical biliary pain and normal trans-abdominal ultrasound (TUS) scan, and can help identify patients who may benefit from cholecystectomy 7.
• The scan can provide information on the presence and location of biliary obstruction, as well as the function of the gallbladder and bile ducts 5, 6.

Interpretation of HIDA Scan Results

• The results of the HIDA scan are interpreted based on the visualization of the gallbladder, bile ducts, and duodenum, as well as the rate of uptake and excretion of the tracer 3, 4, 6.
• Abnormal results may indicate biliary obstruction, gallbladder disease, or hepatocellular disease, and may require further evaluation and treatment 3, 4, 6.