A gallbladder scan is a nuclear scanning test that checks to see how your gallbladder is working. The scan can find blockage in the tubes (bile ducts) that lead from the liver to the gallbladder and small intestine (duodenum).
During a gallbladder scan, a radioactive tracer substance is put into a vein in the arm. The liver removes the tracer from the blood and adds it to the bile that normally flows through the bile ducts to the gallbladder. The gallbladder then releases the tracer into the first part of the small intestine. A special camera 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:
- Help find the cause of pain in the upper right side of the belly.
- Check the function of the gallbladder. A gallbladder ultrasound may be done before a gallbladder scan. This can help find problems in the gallbladder. If the ultrasound is normal, a gallbladder scan often is done to see how well the gallbladder is working.
- Help find the cause of jaundice.
- Find blockage of the bile ducts that lead from the liver to the gallbladder and small intestine (duodenum).
- Look for bile that has leaked after surgery or an injury.
How To Prepare
Before your gallbladder scan, tell your doctor if:
- You are or might be pregnant.
- You are breastfeeding. The radioactive tracer used in this test can get into your breast milk. Do not breastfeed your baby for 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. Throw away the breast milk you pump for 2 days after the test.
- Within the past 4 days, you have had an X-ray test using barium contrast material (such as a barium enema) or have taken a medicine (such as Pepto-Bismol) that contains bismuth. Barium and bismuth can affect the test.
Do not eat or drink for 4 to 12 hours before a gallbladder scan. Your doctor will tell you how long you should not eat or drink. This depends on what the test is being done for.
You may be asked to sign a consent form before the test.
Talk to your doctor if you have any concerns about 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 .
How It Is Done
You will need to take off any jewelry that might affect the scan. You may need to take off all or most of your clothes. This depends on which part of your body is being examined. You may be allowed to keep on your underwear if it does not affect the test. You will be given a cloth or paper covering to use during the test.
During the test
The site on your arm where the radioactive tracer goes in will be cleaned. A small amount of the tracer is then injected.
You will lie on your back on a table. A large scanning camera will be placed just above your belly. After the radioactive tracer is injected, the camera will scan for radiation released by the tracer. The camera makes pictures as the tracer passes through your liver and into your gallbladder and small intestine. The first pictures will be taken right after the tracer starts to go in. The pictures may be continuous, like a video. Or they may be taken once in a while for up to 1½ hours after the test starts.
Each scan takes only a few minutes. You need to lie very still during each scan so the pictures won't be blurred. The camera does not produce any radiation. So you are not exposed to any more radiation while the scan is being done.
A substance that stimulates the gallbladder may also be put into your vein during the scans. The pictures taken after this injection can help see if the gallbladder is working normally. A computer may look at the data to check how well the gallbladder is working. You may be asked about your reaction to the substance used to stimulate the gallbladder. Sometimes medicine (morphine sulfate) is given to help find out if the gallbladder is inflamed.
The gallbladder scan takes about 1 to 2 hours.
After the test
Depending on your results, more scans may be taken up to a day later. If you need to go back for another gallbladder scan, do not eat any fatty foods before the test.
How It Feels
You may feel nothing at all from the needle, or you may feel a brief sting or pinch. Otherwise, a gallbladder scan usually doesn't hurt.
You may find it hard to stay still during the scan. Ask for a pillow or a blanket to get as comfortable as you can before the scan starts.
The test may be uncomfortable if you are having pain in your belly. Try to relax by breathing slowly and deeply.
You may have nausea or belly pain if a substance that stimulates the gallbladder is used during the test. You may be asked about changes in your pain during the test.
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.
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.
The radioactive tracer flows evenly through the liver and then into the gallbladder and the first part of the small intestine (duodenum).
The gallbladder is normal in size, shape, and location.
The tracer may not be removed normally from the blood by the liver. This may be a sign of liver disease.
The gallbladder does not contract or empty normally.
The tracer may not reach the gallbladder. This means there is swelling or that the duct is blocked by a gallstone.
The tracer may not reach the first part of the small intestine (duodenum). This may mean a bile duct is blocked by a stone. Or there may be a tumor, infection, or swelling of the pancreas.
Pain occurs when the gallbladder empties the tracer.
What Affects the Test
You may not be able to have the test, or the results may not be helpful, if:
- You are pregnant. A gallbladder scan is not usually done during pregnancy. This is because the radiation could hurt the unborn baby.
- You have recently had a test that uses barium or taken a medicine that contains bismuth (such as Pepto-Bismol).
- You are not able to stay still during the test.
- You are allergic to morphine.
What To Think About
- A gallbladder ultrasound test may also be done to find problems of the gallbladder. Ultrasound tells more about the shape and size of the gallbladder than a nuclear scan does. But the nuclear scan can show how well the gallbladder is working and whether the bile ducts are blocked. To learn more, see the topic Abdominal Ultrasound.
- The results of a gallbladder scan should be looked at along with your symptoms. They should also be looked at with the results of other tests, such as a physical exam and an ultrasound. Abnormal results from a gallbladder scan do not always mean that the gallbladder needs to be removed.
- A test called endoscopic retrograde cholangiopancreatogram (ERCP) can be done to find blockage of the bile duct. To learn more, see the topic Endoscopic Retrograde Cholangiopancreatogram (ERCP).
- A test called MR cholangiopancreatogram (MRCP) may also be done to find blockage of the bile duct. This is a type of magnetic resonance imaging (MRI) test.
Current as of: April 15, 2020
Author: Healthwise Staff
Medical Review: Adam Husney MD - Family Medicine
Howard Schaff MD - Diagnostic Radiology