Gallium (Ga.) scan

Definition

A gallium scan is a nuclear medicine examination using a radioactive material (gallium) to look for areas of hidden infection in the body.

How the test is performed

A rubber strap (tourniquet) is tied around the upper arm to help locate the vein, and the gallium is injected into the vein.

The scan is taken with a special camera that detects where the gallium has accumulated in the body. If acute inflammatory disease is suspected, the scan is performed 4 to 6 hours after injection; otherwise the scan is taken 24 to 48 hours (occasionally 72 hours) after the injection. During the scan, which takes 30 to 60 minutes, the patient must remain still.

This test usually does not require a stay in the hospital.

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 to 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.

Illustrations

Gallium injection

Page Content:

Liver gallium scan; Bony gallium scan