Gallium Scan
Test OverviewA gallium scan is a
nuclear medicine test that can check for problem areas in certain tissues in your body. A radioactive tracer (tracer) called gallium
citrate is injected into a vein in your arm. It moves through your bloodstream and into certain tissues. These tissues include your bones, liver, and intestine, and areas that are inflamed or have a buildup of
white blood cells. After the tracer builds up in your body, a special camera takes pictures. The pictures show the areas where
the amount of tracer is higher than normal. These areas are called hot spots. It often takes
the tracer a few days to build up. So the pictures (scans) are usually taken
at 2 days and again at 3 days after you get the tracer. The tracer stays
in you until your body gets rids of it through urine or stool
(feces). Why It Is DoneA gallium scan is done to: - Find the source of an infection that is
causing a fever.
- Look for an
abscess or certain infections, especially in the
bones.
- Check the response to
antibiotic treatment.
- Diagnose
inflammatory problems such as
pulmonary fibrosis or
sarcoidosis.
- Find certain types of
cancer (such as
lymphoma). The scan also may be done to see if
cancer has spread (metastasized) to other areas of the body. Or it may check how
well a cancer treatment is working.
How To PrepareBefore this test, tell your
doctor if: - You are or might be pregnant.
- You
are breastfeeding.
- If you plan to no longer feed your baby your breast milk after the test, stop breastfeeding 2 weeks before the test. The
radioactive tracer will not build up in your breast tissue.
- If you will
continue to breastfeed after the test, talk with your doctor about how long to wait to use your milk after the test. Many doctors suggest waiting 4 weeks before you give your breast milk to your baby. This is because the tracer can pass to your baby. Some doctors may advise you to stop breastfeeding completely
after this scan.
- Within the 4 days before the scan, you have:
- Had an X-ray test using barium
contrast material. This includes a
barium enema.
- Taken a medicine that contains bismuth, such as Pepto-Bismol.
Barium and bismuth can affect the test
results.
Gallium builds up in the large intestine before your body gets rid of it as stool. So you may need to take a laxative the night before
the scan. You may also need an enema 1 to 2 hours before the scan. This is to help your doctor more clearly see the areas of your body that are being studied. Talk to your doctor about any concerns you have 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 DoneA gallium scan is usually done by a
nuclear medicine technologist. In most cases, a
radiologist or
nuclear medicine specialist will interpret the scan pictures. The
technologist will clean a site on your arm and then inject a small amount of radioactive tracer. You will
need to come back for the scans. Gallium
scans are usually done 24 hours (1 day), 48 hours (2 days), and 72 hours (3 days)
after the tracer is injected. When you come in for the scan, you
may need to remove your jewelry. You may
also need to take off all or most of your clothes. It depends on which area is being
examined. You will be given a cloth or paper to cover yourself during the
test. You will lie on your back on a table. A large camera will be close above you. The camera will scan for radiation released by the tracer. It will make
pictures of the tracer in your tissues. The camera may move slowly above and
around your body. The camera does not produce any radiation, so you are not
exposed to more radiation while the scan is being done. You may be asked to move into different positions so the area of interest
can be viewed from other angles. You need to lie very still during each scan to
avoid blurring the pictures. You may be asked to hold your breath briefly
during some of the scans. Each scan may take about 60 to 90
minutes. How It FeelsYou 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 gallium scan usually causes no pain. You may find it hard to stay still during the scan. Ask for a
pillow or blanket to make yourself as comfortable as you can before the scan
begins. RisksThere is always a slight risk of damage to
cells or tissue from being exposed to any radiation. The tracer used for this test gives off a low level of
radiation. Allergic reactions to the tracer are rare.
Your body will get rid of most of the tracer (through your urine or
stool) within 4 days. The amount of radiation is very small. So it is not a risk
for people to come in contact with you after the test.
Your injection site may swell or be sore. To get relief, you can apply a moist, warm compress to your
arm. ResultsA gallium scan is a
nuclear medicine test. A special camera takes pictures of certain tissues in the body after a radioactive tracer
makes the tissues able to be seen. The test results are usually ready within 2 days after you had the scans. Gallium scan| Normal: | The collection and activity of gallium in
the bones, liver, spleen, and large intestine is normal. No areas of
unusual amounts of gallium are seen. |
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| Abnormal: | An abnormally high amount of gallium (hot spot) is present in one or more areas of the body. This could mean
inflammation, infection, or a tumor. |
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What Affects the TestYou may not be able to
have the test, or the results may not be helpful, if: - You are pregnant. A gallium scan is not usually done
during pregnancy because the radiation could harm the baby (fetus).
- You have barium or bismuth in your
system. If a gallium scan is needed, it should be done before any tests that
use barium (such as a
barium enema). Taking a medicine (such as
Pepto-Bismol) that contains bismuth can also affect the test.
- You can't stay still during the test.
What To Think About- A gallium scan is used for certain types of
cancers. Mainly it's for cancers of the
lymph nodes, bones, or
bone marrow. A normal scan does not rule out the
possibility of cancer, though. That's because some types of cancer don't show up on a gallium
scan. This type of scan also can't tell if a tumor is cancerous
(malignant) or noncancerous (benign).
- Your doctor will interpret the results of the scan along with the results of other tests, such as a physical
exam, blood tests, and X-rays. In many cases, results from an
MRI test or positron emission tomography (PET) scan may be as accurate as the results from a gallium
scan.
- If
other nuclear scanning tests need to be done, they should be scheduled
before a gallium scan. This is because the gallium tracer stays in the body longer than
other tracer compounds.
ReferencesOther 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.
CreditsByHealthwise Staff
Primary Medical ReviewerKathleen Romito, MD - Family Medicine
Adam Husney, MD - Family Medicine
Martin J. Gabica, MD - Family Medicine
Specialist Medical ReviewerHoward Schaff, MD - Diagnostic Radiology Current as ofOctober 14, 2016 Current as of:
October 14, 2016 Last modified on: 8 September 2017
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