A gallium scan is usually done by a nuclear medicine technologist. In most cases, a radiologist or nuclear medicine specialist will interpret the scan pictures.

The technologist will clean a site on your arm and then inject a small amount of radioactive tracer. You will need to come back for the scans. Gallium scans are usually done 24 hours (1 day), 48 hours (2 days), and 72 hours (3 days) after the tracer is injected.

When you come in for the scan, you may need to remove your jewellery. You may also need to take off all or most of your clothes. It depends on which area is being examined. You will be given a cloth or paper to cover yourself during the test.

You will lie on your back on a table. A large camera will be close above you. The camera will scan for radiation released by the tracer. It will make 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 more 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.

You may feel nothing at all from the needle puncture when the tracer is injected. Or you may feel a brief sting or pinch as the needle goes through the skin. Otherwise, a gallium scan usually causes no pain. You may find it hard to stay still during the scan. Ask for a pillow or blanket to make yourself as comfortable as you can before the scan begins.

Allergic reactions to the tracer are rare.

Your injection site may swell or be sore. To get relief, you can apply a moist, warm compress to your arm.

Anytime you're exposed to radiation, there's a small chance of damage to cells or tissue. That's the case even with the low-level radioactive tracer used for this test. But the chance of damage is very low compared with the benefits of the test.

Most of the tracer will leave your body through your urine or stool within a day. So be sure to flush the toilet right after you use it, and wash your hands well with soap and water. The amount of radiation in the tracer is very small. This means it isn't a risk for people to be around you after the test.

Many doctors suggest waiting 4 weeks before you give your breast milk to your baby. This is because the tracer can pass to your baby. Some doctors may advise you to stop breastfeeding completely after this scan.

The test results are usually ready within 2 days after you had the scans.