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Gallium (Ga.) scan
Definition A gallium scan is a test that uses radioactive material to look for infection in the body. It is a type of nuclear medicine exam. Alternative Names Liver gallium scan; Bony gallium scan How the test is performed The health care provider will tie a rubber band (tourniquet) around your upper arm, and then inject a radioactive material called gallium into a vein. A special camera detects where the gallium has gathered in the body. If the doctor thinks you have an acute inflammatory disease, the scan is done 4 - 6 hours after the injection. Otherwise, the scan is taken 24 - 48 hours (occasionally 72 hours) after the injection. You must lie still during the scan, which takes 30 - 60 minutes. See also: Gallium scan of the lung How to prepare for the test The night before the test, a laxative may be necessary to clean out the bowel so that stool does not interfere with the test. An enema may instead be given 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 enema may be uncomfortable but does not cause pain. The injection will feel like a sharp prick, and the site may be tender to the touch for a few minutes. The hardest part of the scan is holding still, as the scan itself is painless. Before the scan, some adjustments may be made to make the patient more comfortable. Why the test is performed This test may be performed in the search for an unknown source of fevers. Gallium collects in areas of inflammation, which may be due to an abscess or tumor. Combined with other imaging, such as CT, hidden disease may be detected. Normal Values Gallium normally collects in bones, the liver, spleen, the large bowel, and breast tissue. What abnormal results mean Gallium detected outside the normal areas (areas of increased uptake) can indicate infection, inflammation, or possibly tumors, including Hodgkin's disease or non-Hodgkin's lymphoma. What the risks are There is a minimal risk of radiation exposure (less than with x-rays or CT scans). Radiation exposure of any sort is not usually recommended for pregnant or nursing women or for young children unless the benefits of the test exceed the risks. Special considerations Not all cancers show up on a gallium scan. References Society of Nuclear Medicine. Procedure guideline for gallium scintigraphy in inflammation. 3rd ed. Reston, VA: Society of Nuclear Medicine; June 2, 2004: 5. Review date: 1/24/2007 Reviewed By: Stuart Bentley-Hibbert, MD, PhD, Department of Radiology, Weill Cornell Medical Center, New York, NY. Review provided by VeriMed Healthcare Network.
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