Gallium Scan

Overview

A gallium scan is a nuclear medicine test that 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 the tracer decreases over a period of weeks. It remains in the body temporarily before 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 is present. It usually takes the tracer a few days to accumulate in these areas, so in most cases a scan is done at 2 days and repeated at 3 days after the tracer is injected. Areas where the tracer accumulates 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.

Test Procedure

A gallium scan is usually done by a nuclear medicine technologist. The scan pictures are usually interpreted by a radiologist or nuclear medicine specialist.

The technologist cleans the site on your arm where the radioactive tracer will be injected. A small amount of the radioactive tracer is then injected. You will need to return between 24 and 96 hours later for the diagnostic scans. Gallium scans are usually done at 48 hours and repeated at 72 hours after the tracer is injected.

When you come in for the scan, you will need to remove any jewelry that might interfere with the scan. You may need to take off all or most of your clothes; depending on which area is being examined (you may be allowed to keep on your underwear if it does not interfere with the test). You will be given a cloth or paper covering to use during the test.

You will lie on your back on a table, and a large scanning camera will be positioned closely above you. After the radioactive tracer is injected, the camera will scan for radiation released by the tracer and produce 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 any additional 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.

Test Results

It can take time for the test results and how long will depend on the reasons for the scan. Usually, a specialist in radiology examines the scan and a report sent to your physician, who reviews the results to you.