A HIDA (hepatobiliary iminodiacetic acid ) scan is an imaging test. It can be used to check for problems in the liver, gallbladder, and the tubes inside and outside the liver (bile ducts).

During the test, a small amount of radioactive substance (tracer) is injected into a vein in your arm or hand. Pictures are then taken to track the movement of the tracer. The test takes about 2 hours. In some cases, more pictures may need to be taken after a wait of 4 hours. You'll be told as the test progresses how long your test may take.

• Follow any directions you're given for not eating or drinking before the procedure. Your doctor will give you instructions if required.
• Tell your doctor what medicines you're taking. This includes vitamins, herbs, and over-the-counter medicines. You may be told to stop taking some or all of them in the days before the test.
• Follow any other instructions you're given to get ready for the test.

Let the technologist know if you:

• Are taking any medicines or have allergies to any medicines. Some medicines may prevent accurate test results.
• Had recent X-rays or tests that used barium.
• Had recent surgery or illness.
• Have other health problems, such as diabetes.
• Are pregnant or think you might be pregnant.
• Are breastfeeding.
• Smoke or use other tobacco products.

The test is done by a nuclear medicine or radiology technologist. It can be done in a hospital or test center.

• You'll lie on your back on a table. A special camera (also called a scanner) will be positioned above your belly (abdomen).
• An I.V. (intravenous) needle or I.V. line is placed into a vein in your arm or hand. The tracer is then injected through the I.V. line.
• Pictures are taken as the tracer follows the movement of bile through the liver, gallbladder, and bile ducts, and the first part of the small intestine (duodenum). Bile is a substance made by the liver that helps you digest fat.
• You'll need to lie still to help ensure that the pictures are not blurry.
• You may be given a substance by mouth or injected through a vein that causes the gallbladder to contract and release bile. Be sure to let the technologist know if you feel discomfort. This could indicate gallbladder dysfunction.
• If needed, more pictures may be taken after 4 hours.

• The technologist will let you know when the test is completed.
• The tracer will pass out of the body in your stool and urine within 24 hours. Drink plenty of fluids to help the tracer pass.

Your doctor will go over test results with you when they are ready. This is likely within a few days of the test.

Possible risks of this imaging test can include:

• Problems at the I.V. site.
• Allergic reaction to the tracer or medicine used during the test.
• Radiation exposure from the tracer.