Test Overview
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(What is a PDF document?).
How It Is Done
A gallbladder scan is usually done by a
nuclear medicine technologist. The scan pictures are usually read by a
radiologist or
nuclear medicine specialist.
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.
Risks
Allergic reactions to the radioactive
tracer are rare. Most of the tracer will leave your body through
your urine or stool within a day. So be sure to flush the toilet right away after each use. And wash your hands well 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 after
the test.
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.
There is always a slight chance of
damage to cells or tissue from radiation, including the
low level of radiation used for this
test. But the chance of damage is usually very low compared with the benefits of the test.
Results
A gallbladder scan is a special
nuclear scanning test that is done to check how the
gallbladder is working. The results of a gallbladder
scan are ready in 2 days.
Gallbladder scan| Normal: | 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. |
| Abnormal: | 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.
References
Other Works Consulted
- Chernecky CC, Berger BJ (2008). Laboratory Tests and Diagnostic Procedures, 5th ed. St. Louis: Saunders.
- Fischbach FT, Dunning MB III, eds. (2009). Manual of Laboratory and Diagnostic Tests, 8th ed. Philadelphia: Lippincott Williams and Wilkins.
- Pagana KD, Pagana TJ (2010). Mosby's Manual of Diagnostic and Laboratory Tests, 4th ed. St. Louis: Mosby Elsevier.
Credits
ByHealthwise Staff
Primary Medical ReviewerAdam Husney, MD - Family Medicine
Specialist Medical ReviewerHoward Schaff, MD - Diagnostic Radiology