The technician will inject a radioactive material called gallium into a vein. The gallium travels through the bloodstream and collects in the bones and certain organs.
Your health care provider will tell you to return at a later time to be scanned. The scan will be taken 6 - 24 hours after the gallium is injected. The test time depends on what condition your doctor is looking for.
You will lie on your back on the scanner table. A special camera detects where the gallium has gathered in the body.
You must lie still during the scan, which takes 30 - 60 minutes.
How to prepare for the test
The night before the test, you may need a laxative to clean out the bowel so that stool does not interfere with the test. Or, you may get an enema 1 - 2 hours before the test.
Food and liquids are not restricted.
You must sign a consent form. Remove all jewelry and metal objects.
How the test will feel
The injection will feel like a sharp prick. The site may be tender to the touch for a few minutes.
The hardest part of the scan is holding still. The scan itself is painless. The technician can help make you comfortable before the scan begins.
Why the test is performed
This test may be done to search for an unknown source of fevers. It is most often used for a cancer of the lymph system called lymphoma.
Gallium normally collects in bones, the liver, spleen, the large bowel, and breast tissue.
What abnormal results mean
Gallium detected outside normal areas can be a sign of:
There is a small risk of radiation exposure (less than with x-rays or CT scans). Radiation exposure of any kind is not usually recommended for pregnant or nursing women or for young children unless it cannot be avoided.
Not all cancers show up on a gallium scan.
Segerman D, Miles KA. Radionuclide imaging: general principles. In: Adam A, Dixon AK, eds. Grainger & Allison's Diagnostic Radiology: A Textbook of Medical Imaging. 5th ed. New York, NY: Churchill Livingstone;2008:chap 7.
Vinnicombe SJ, Reznek RH. Reticuloendothelial disorders: lymphoma. In: Adam A, Dixon AK, eds. Grainger & Allison's Diagnostic Radiology: A Textbook of Medical Imaging. 5th ed. New York, NY: Churchill Livingstone;2008:chap 72.
David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.