What Is a Hepatobiliary Iminodiacetic Acid (HIDA) Scan?

What to expect when undergoing this test

A hepatobiliary iminodiacetic acid (HIDA) scan, which is also sometimes called a cholescintigraphy or hepatobiliary scintigraphy, is a type of nuclear imaging test that’s done to view the bile ducts, gallbladder, and liver. This test is done by injecting a tracer which contains a small amount of radioactive material into the blood and then taking images of the abdomen in order to visualize how the tracer moves through the body. The test gives a picture of how the gallbladder and liver are working and may take about an hour to complete. 

what to expect during a HIDA Scan
Illustration by Emily Roberts, Verywell

Purpose of the Test

A HIDA scan might be used to diagnose problems with the gallbladder, how the liver excretes bile, and the flow of bile as it leaves the liver and enters the small intestine. An x-ray and an abdominal ultrasound might also be done along with the HIDA. Some of the conditions that might be diagnosed or evaluated with this test include:

  • Biliary atresia or other congenital bile duct conditions 
  • Leaks or complications in the biliary system (such as fistulas)
  • Inflammation of the gallbladder (cholecystitis)
  • Blockage of the bile duct
  • Post liver transplant assessment

Risks and Contraindications

A HIDA is a nuclear medicine test, and this type of test isn't usually done in pregnant women. Therefore, if there’s a chance of pregnancy, women should let their doctor or the radiology staff know before having the test. Women should also let their doctor know if they are breastfeeding, as this may also affect the decision to have this test

The risks of the HIDA scan are mostly related to the tracer or the drugs that are administered in order to complete the test. Risks of the HIDA scan are low but they can include:

  • Allergic reactions to the substances used during the test (which is rare)
  • A bruise, rash, or swelling where the tracer is injected
  • A small exposure to radiation

Before the Test

A physician or the radiology staff will give instructions on how to prepare for the test. It’s important to tell the doctor about any current medications or supplements in order to get instructions on when or how to take them on the day of the test. In some cases, a drug that’s needed for the test may need to be taken at home prior to coming into the radiology center.

Timing

Because this test is not only to view the structures in the body but also to observe the tracer as it moves through the liver, the gallbladder, the bile duct, and into the small intestine, this test may take, on average, between an hour and an hour and a half to complete, but in some cases may take as long as four hours. Ask your doctor how much time to allot for the appointment.

What to Wear

For a HIDA test it will likely be necessary to remove clothing and change into a hospital gown. Any metal objects will also need to be taken off (including piercings), so it may be easier to leave jewelry at home.

Food or Drink

Usually, it’s necessary to stop eating or drinking anything for about 4 hours before the test. In some cases, clear liquids (such as water, plain tea or coffee, apple juice, lemonade, or lemon/lime soft drinks) might be allowed during the fasting period.

What to Bring

This test does not require you to bring anything special. Make sure you have your health insurance card, if needed, and consider bringing something to do while you're waiting (read a book, for example).

During the Test

A HIDA scan will be performed by the imaging technicians at the hospital or radiology center.

Pre-Test

Patients will usually be asked to fill out some forms and answer a few questions such as medications being taken, any surgeries (especially anything on the abdomen), and for women, about a current pregnancy and/or the date of the last menstrual period.

Throughout the Test

The HIDA scan involves taking images of the abdomen, so patients are asked to lie on their back on a table. After getting comfortable, the imaging technician will inject the tracer into one arm. There may be a cold feeling or a feeling of pressure during the injection. In some cases, other drugs may also be injected, including Kinevac (sincalide) or cholecystokinin (CCK), which activate the gallbladder, and morphine, which may help guide the tracer to the gallbladder. Morphine is a pain medication, and it may cause drowsiness.

Similar to an x-ray, it’s important to stay still during this test so that clear images can be taken. The imaging technician will move a gamma camera over the abdomen in order to take images of the tracer as it moves through the body.

Post-Test

The imaging team will give instructions about any restrictions for the rest of the day, but after the test is over, most people will be able to have some food and go about their day. The tracer will pass through the body and be excreted in stool or urine.

After the Test

There are typically no special instructions to follow after the test is over, but if there is something unique to your situation the healthcare team will let you know.

There are no side effects to manage after the test. The radioactivity of the tracer only lasts for a few hours, so it’s no longer radioactive by the time the test is over. It’s important to drink water to help the tracer pass out of the body more quickly though.

Note that if you received morphine, you should not drive yourself home. Plan to have someone pick you up or a cab available.

Interpreting Results

A physician will explain the results of the test and what, if any, are next steps to take. It’s important that the results be discussed with a doctor so that they can be put in the proper perspective. The test could show one of several results:

  • The tracer moved through the gallbladder and small intestine normally, or as expected.
  • The tracer moved slower than expected, which could be the result of an obstruction or blockage in a bile duct or an irregularity in liver function. 
  • The tracer did not enter the gallbladder, which may mean that the gallbladder is inflamed (which is called acute cholecystitis).
  • The tracer left the gallbladder in amounts lower than what is expected, which could mean that the gallbladder is chronically inflamed, a condition called chronic cholecystitis.
  • The tracer is found outside the biliary system, which could mean that there’s a leak in the bile duct system or a perforation in the gallbladder.

A Word from Verywell

A HIDA scan is a test that’s non-invasive, though it may require blocking out part of a day to get it done. This nuclear imaging test can provide information to a physician about the biliary system, and in particular, the gallbladder, so it may help in getting answers to why signs and symptoms are occurring. It’s important to discuss the results thoroughly with a physician in order to understand what they might mean for future treatment or management.

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Article Sources
  • Mahid SS, Jafri NS, Brangers BC, et al. Meta-analysis of Cholecystectomy in Symptomatic Patients With Positive Hepatobiliary Iminodiacetic Acid Scan Results Without Gallstones. Arch Surg. 2009;144:180–187. doi:10.1001/archsurg.2008.543
  • Tulchinsky M, Ciak BW, Delbeke D, et al; Society of Nuclear Medicine. SNM practice guideline for hepatobiliary scintigraphy 4.0. J Nucl Med Technol. 2010 Dec;38:210-218. doi: 10.2967/jnmt.110.082289