What is a Hepatobiliary Iminodiacetic Acid (HIDA) scan?

From the Guidelines

A HIDA scan is the most sensitive and specific test for diagnosing acute calculus cholecystitis (ACC) and should be used as the primary imaging modality in selected patients. The procedure 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 1.

Key Points to Consider

• The HIDA scan has the highest sensitivity and specificity for diagnosing ACC compared to other imaging modalities, such as computed tomography (CT) and magnetic resonance imaging (MRI) 1.
• Before the procedure, patients should fast for 4-6 hours, though specific preparation instructions may vary 1.
• During the scan, the patient will lie on an examination table while a special camera takes pictures for about an hour as the tracer moves through their system 1.
• Sometimes, a medication called cholecystokinin (CCK) is administered to stimulate gallbladder contraction 1.
• The test is generally safe with minimal radiation exposure, though pregnant women should inform their doctor beforehand.
• Results are typically available within 24-48 hours, and the radioactive material naturally leaves the body within a day.

Procedure Details

• The presincalide procedure involves injecting an HIDA radiotracer intravenously with the patient supine on the imaging table 1.
• Imaging should be obtained up to 1 hour to ensure visualization of the gallbladder prior to sincalide infusion 1.
• If the gallbladder has not filled by 60 minutes in a properly prepared patient, the finding is reported as abnormal, potentially consistent with either acute or chronic cholecystitis depending upon the clinical presentation 1.

From the FDA Drug Label

CLINICAL PHARMACOLOGY Mebrofenin is an iminodiacetic acid (HIDA) derivative with no known pharmacologic action at the recommended doses. Following intravenous administration in normal subjects, Technetium Tc 99m Mebrofenin was rapidly cleared from the circulation. The mean percent injected dose remaining in the blood at 10 minutes was 17% 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. Hepatic duct and gallbladder visualization occurred by 10 to 15 minutes and intestinal activity was visualized by 30 to 60 minutes in subjects with normal hepatobiliary function. PRECAUTIONS General Contents of the reaction vial are intended only for use in the preparation of Technetium Tc 99m Mebrofenin and are not to be administered directly to the patient. Delayed or non-visualization of the gallbladder may occur in the immediate post-prandial period or after prolonged fasting or parenteral feeding Functional biliary obstruction may accompany chronic cholecystitis or pancreatitis. In addition, patients with hepatocellular disease may show non-visualization or delayed visualization of the gallbladder.

Hida Scan:

• The Hida scan uses Technetium Tc 99m Mebrofenin to visualize the liver, hepatic duct, gallbladder, and intestine.
• The scan can be used to evaluate hepatobiliary function and biliary obstruction.
• Delayed or non-visualization of the gallbladder may occur in certain conditions, such as chronic cholecystitis, pancreatitis, or hepatocellular disease 2, 2.
• The scan results should be evaluated in the context of the total clinical picture and results of other diagnostic modalities.

From the Research

HIDA Scan Overview

• A HIDA scan is a medical imaging test used to evaluate the function and structure of the gallbladder and biliary system [ 3 ].
• The scan uses a small amount of radioactive material, typically technetium-99m labelled HIDA, which is taken up by the liver and excreted into the biliary tree [ 3 ].

Clinical Applications

• HIDA scans are useful in diagnosing acute gallbladder disease, with a high correlation between abnormal scans and gallbladder pathology [ 4 ].
• The scan can also help identify biliary obstruction, chronic gallbladder disease, and hepatocellular disease [ 3 ].
• In patients with typical biliary pain and normal trans-abdominal ultrasound, a HIDA scan can help diagnose chronic cholecystitis and guide treatment [ 5 ].

Diagnostic Accuracy

• The sensitivity and specificity of HIDA scans vary depending on the clinical context and patient population [ 6 ].
• In patients with hyperbilirubinemia, the sensitivity of HIDA scans may be lower due to impaired uptake and excretion of the radioactive material [ 6 ].
• Nonvisualization of the gallbladder on a HIDA scan is highly suggestive of cholecystitis, particularly acute cholecystitis [ 7 ].

Limitations and Potential Biases

• HIDA scans may not be reliable in patients with severe liver dysfunction or hyperbilirubinemia [ 6 ].
• The scan may not provide diagnostic information in cases where the gallbladder is not visualized, and additional testing may be necessary [ 7 ].