A gallbladder scan is a nuclear scanning test that is done to check gallbladder function. The scan can find blockage in the tubes (bile ducts) that lead from the liver to the gallbladder and small intestine (duodenum). See a picture of the gallbladder and the duodenum.
During a gallbladder scan, a radioactive tracer substance is injected into a vein in the arm. The liver removes the tracer from the bloodstream and adds it to the bile that normally flows through the bile ducts to the gallbladder. The gallbladder then releases the tracer into the beginning of the small intestine. A special camera (gamma) takes pictures of the tracer as it moves through the liver, bile ducts, gallbladder, and small intestine.
Why It Is Done
A gallbladder scan is done to:
How To Prepare
Before your gallbladder scan, tell your doctor if:
Do not eat or drink for 4 to 12 hours before a gallbladder scan. Your doctor will tell you how long depending on what the test is being done for.
You may be asked to sign a consent form before the test. Talk to your doctor about any concerns you have regarding the need for the test, its risks, how it will be done, or what the results will mean. To help you understand the importance of this test, fill out the medical test information form(What is a PDF document?).
How It Is Done
You will need to remove any jewelry that might interfere with the scan. You may need to take off all or most of your clothes, depending on which area is being examined (you may be allowed to keep on your underwear if it does not interfere with the test). You will be given a cloth or paper covering to use during the test.
The technologist cleans the site on your arm where the radioactive tracer will be injected. A small amount of the radioactive tracer is then injected.
You will lie on your back on a table and a large scanning camera will be positioned closely above your abdomen. After the radioactive tracer is injected, the camera will scan for radiation released by the tracer and produce pictures as the tracer passes through your liver and into your gallbladder and small intestine. The first pictures will be taken right after the injection. The pictures may be continuous (like a video) or may be taken once in a while for up to the next 1½ hours. Each scan takes only a few minutes. You need to lie very still during each scan to avoid blurring the pictures. The camera does not produce any radiation, so you are not exposed to any additional radiation while the scan is being done.
A substance (cholecystokinin) that stimulates the gallbladder may also be injected into your vein during the scans. The pictures taken after this injection can help determine whether the gallbladder is functioning normally. Computer analysis of the data may be used to check gallbladder function. You may be asked to answer questions about your reaction to the cholecystokinin. Occasionally medicine (morphine sulfate) is given to help diagnose inflammation of the gallbladder.
Depending upon your results, additional scans may be taken up to a day later. If you need to return for another gallbladder scan, you should not eat any fatty foods before you return.
The gallbladder scan takes about 1 to 2 hours.
How It Feels
You may feel nothing at all from the needle puncture when the tracer is injected, or you may feel a brief sting or pinch as the needle goes through the skin. Otherwise, a gallbladder scan is usually painless. You may find it hard to remain still during the scan. Ask for a pillow or blanket to make yourself as comfortable as possible before the scan begins.
The test may be uncomfortable if you are having abdominal pain. Try to relax by breathing slowly and deeply.
If cholecystokinin is used during the test, it may cause nausea or abdominal pain. The technologist may ask you about changes in your pain during the test.
Allergic reactions to the radioactive tracer are rare. Most of the tracer will be eliminated from your body (through your urine or stool) within a day, so be sure to promptly flush the toilet and thoroughly wash your hands with soap and water. The amount of radiation is so small that it is not a risk for people to come in contact with you following the test.
Occasionally, some soreness or swelling may develop at the injection site. These symptoms can usually be relieved by applying moist, warm compresses to your arm.
There is always a slight risk of damage to cells or tissue from being exposed to any radiation, including the low level of radiation released by the radioactive tracer used for this test.
What Affects the Test
Reasons you may not be able to have the test or why the results may not be helpful include:
What To Think About
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