A gallium scan is a
nuclear medicine test. A nuclear medicine test uses a
special camera to take pictures of specific tissues in the body after a
radioactive tracer (radionuclide or radioisotope) makes them visible. Each type
of tissue that may be scanned (including bones, organs, glands, and blood
vessels) uses a different radioactive compound as a tracer. The radioactivity
of a tracer decreases over a period of hours, days, or weeks. The tracer stays
in the body until it is eliminated as waste, usually in the urine or stool
During a gallium scan, the tracer (radioactive gallium
citrate) is injected into a vein in the arm. It travels through the bloodstream
and into the body's tissues, primarily the bones, liver, intestine, and areas
of tissue where inflammation or a buildup of
white blood cells (WBCs) is present. It often takes
the tracer a few days to build up in these areas, so in most cases a scan is
done at 2 days and again at 3 days after the tracer is injected. Areas where
the tracer builds up in higher-than-normal amounts show up as bright or "hot"
spots in the pictures. The problem areas may be caused by infection, certain
inflammatory diseases, or a tumor.
Why It Is Done
A gallium scan is done to:
- Detect the source of an infection that is
causing a fever (called a fever of unknown origin).
- Detect an
abscess or certain infections, especially in the
- Monitor the response to
inflammatory conditions such as
pulmonary fibrosis or
- Detect certain types of
cancer (such as
lymphoma). A gallium scan also may be done to see if
cancer has spread (metastasized) to other areas of the body, or to watch how
well a cancer treatment is working.
How To Prepare
Before the gallium scan, tell your
- You are or might be pregnant.
are breast-feeding. If you will no longer be breast-feeding after the test, you
will be asked to stop breast-feeding 2 weeks before the test so that the
radioactive tracer will not build up in your breast tissue. If you will
continue to breast-feed after the test, it is recommended that you not use your
breast milk for 4 weeks after a gallium scan because the tracer can be passed
to your baby. Some doctors may advise you to stop breast-feeding completely
after this scan.
- Within the 4 days before the gallium scan, 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 interfere with test