A gallium scan is a type of imaging test used in medicine to diagnose infections, inflammation, and certain cancers. They are commonly done when you have a fever that your doctor cannot find a cause for. It’s a type of nuclear medicine scan.
In order to do the scan, a very small amount of gallium is injected into your blood before the actual imaging. A camera is used to detect emissions from the gallium after it has had time to spread throughout your body. An image of your entire body is formed during this scan.
How Does a Gallium Scan Work?
Gallium is a radioactive element — this means that it emits high energy particles at unpredictable times, specifically gamma rays. It was the first radioactive element used in a medical nuclear scan.
The gallium collects in cells that are rapidly dividing — creating new cells — and at sites of inflammation.
If you’re exposed to radioactive elements in large quantities for a large amount of time, they can cause cell damage and cancer. But the amount of gallium that's used in this type of scan is as safe as an X-ray.
Newer technologies — such as positron emission tomography (PET) — are quickly replacing gallium scans because they are more efficient and effective. Because of this, gallium scans are not being used as often as they were in the past.
What Should You Do Before a Gallium Scan?
You usually don’t need to do a lot to prepare for a gallium scan. Your doctor will let you know if you need to stop taking any of your medications or follow any other special restrictions.
You may also need to take a laxative for several days before the procedure. The pictures are clearer when your bowels are empty.
Be sure to tell your doctor if you’re pregnant or breastfeeding. Gallium isn’t safe for a growing baby and can get into breastmilk.
How Is the Gallium Scan Procedure Done?
The procedure for a gallium scan typically starts a day or two before the actual scan. The first step is to have the gallium injected in the form of gallium citrate, usually in your arm. The molecule attaches to proteins in your blood and spreads throughout your entire body over the course of the following hours and days.
Your doctor will tell you a very specific time to come back after the injection. This could range from a few hours to days after the injection.
On the day of the appointment, wear comfortable clothes since you’ll need to change into a hospital gown. You’ll also need to remove all jewelry and empty your bladder.
You will lay on your back beneath a special camera that will scan your body with the aid of the gamma rays from the gallium.
The entire procedure will take around an hour.
Your doctor may want you to come back for a second scan while the gallium is still in your system.
When the scan is looking for a tumor, you’ll be imaged both two and three days after your gallium injection. When it’s looking for infection, you’re usually scanned one and two days after the injection.
What Should You Do After a Gallium Scan?
You should be able to go home on the same day as your gallium scan. You may want to drink extra water to help flush out the gallium.
Over the course of the next few days, the gallium will slowly leave your system. You shouldn’t worry about any special clean-up because this small amount of radiation shouldn’t be harmful to those around you.
There is a chance that the injection will cause nausea or a rash. Tell your doctor if these symptoms don’t go away.
Some airports have very sensitive scanners — so it’s important to have a doctor’s note when you fly for up to three months after this scan.
A specialist is needed to analyze the images. Your doctor should have your results a few days after the gallium scan.
What Do Gallium Scan Results Show?
The result of a gallium scan is an image of your entire body. The areas where the gallium has gathered stand out clearly in the image. These areas are usually where cells are quickly dividing.
A gallium scan is helpful for detecting a number of different conditions, including:
- Cancer. Gallium scans will not show all kinds of cancer, but they’re useful for highlighting lymphomas — cancers of the lymph system, which is part of the immune system. These scans also track the progress of a treatment — like chemotherapy — showing changes in a tumor.
- Infections. A gallium scan can detect abscesses — collections of pus, osteomyelitis — and bone infections.
- Inflammation. Types of inflammatory conditions that this scan can detect include pulmonary fibrosis — a lung condition — and sarcoidosis — a rare condition that causes small swollen patches across the skin and in the lungs.
Your doctor will recommend a gallium scan if they think it can help diagnose your medical condition.