HIDA Scan: About This Test

What is it?

A HIDA scan is an imaging test that checks how your gallbladder is working. The gallbladder is a small sac under your liver. It stores bile, a fluid that helps your body digest fats. If there are problems with the gallbladder, such as gallstones, the gallbladder may not store or empty bile properly.

During a HIDA scan, a camera takes pictures of your gallbladder after a radioactive tracer is injected into a vein in your arm. The tracer travels through your liver, gallbladder, bile ducts, and small intestine. The camera takes a series of pictures of the tracer as it moves along. Your doctor can use these pictures to look for leaks, blockages, or any other problems.

Why is this test done?

The HIDA scan may be done to:

• Help find the cause of pain in the upper belly, especially if the pain is on the right side.
• See how well the gallbladder is working.
• Find out if bile is leaking.
• Find anything that may be blocking the bile ducts.

A HIDA scan is sometimes done if an earlier ultrasound test did not give enough information.

How do you prepare for the test?

• If you are breastfeeding, you may want to pump enough breast milk before the test to get through 1 to 2 days of feeding. The radioactive tracer used in this test can get into your breast milk and is not good for the baby.
• The doctor may tell you not to eat or drink anything but water for 4 to 6 hours before the test. Follow all instructions carefully.

How is the test done?

• You will remove any clothing around your belly. You will be given a gown or paper covering to use during the test.
• You will lie on your back on a table.
• A thin tube, called an IV, will be put into a vein in your arm.
• A radioactive tracer chemical will be injected into the I.V. A medicine that stimulates your gallbladder may also be injected.
• The scanning camera will be placed close over your belly.
• A picture will be taken right away. The whole scan may last up to 60 minutes as the tracer passes through your liver and into your gallbladder and small intestine. Several more pictures, each lasting a few minutes, may be taken over the next 2 to 4 hours. Each picture will take only a few minutes, but you will have to lie still for the whole test.

What are the risks of a HIDA scan?

Allergic reactions to the radioactive tracer are rare.

Some people may have soreness or swelling where the needle went in. These symptoms can usually be relieved by putting moist, warm compresses on your arm.

Anytime you're exposed to radiation, there's a small chance of damage to cells or tissue. That's the case even with the low-level radioactive tracer used for this test. But the chance of damage is very low compared with the benefits of the test.

What happens after the test?

• After the test, drink lots of fluids for the next 24 hours to help flush the tracer out of your body.
• The radioactive tracer used in this test can get into your breast milk. Do not breastfeed your baby for 1 or 2 days after this test. During this time, you can give your baby breast milk you stored before the test, or you can give formula. Discard the breast milk you pump in the 1 or 2 days after the test.
• Most of the tracer will leave your body through your urine or stool within a day. So be sure to flush the toilet right after you use it, and wash your hands well with soap and water. The amount of radiation in the tracer is very small. This means it isn't a risk for people to be around you after the test.
• You will probably be able to go home right away.
• You can go back to your usual activities right away.
• Depending on your results, more scans may be taken up to a day later. If you need to go back for another HIDA scan, do not eat any fatty foods before the test.