What is a bone scan procedure?
A bone scan is a nuclear imaging test that can help doctors diagnose and track several types of bone diseases, including bone infections. It can also be used to detect cancer that may have spread to the bone from the tumour's original location.
During the bone scan, a very small amount of radioactive substance called a radiopharmaceutical is injected into your vein. The substance works like a dye but does not stain the tissue. The tracer is absorbed in different amounts, which will be highlighted in the scan. When cells and tissues change, they absorb higher amounts of tracer, which may signal the presence of cancer.
Why do you need a bone scan?
Your doctor may order a bone scan if they think there may be a problem in your bones or if you have experienced bone pain. Bone scans are able to scan the whole skeleton and detect various bone disorders such as:
- Arthritis
- Fractures
- Bone cancers
- Infection of the joints, joint replacements or bones (osteomyelitis)
- Impaired blood supply to bones or death of bone tissue (avascular necrosis)
- Fibrous dysplasia, where abnormal scar-like tissue grow in place of normal bone
- Paget's disease of bone, a disease that causes weak, deformed bones
Who should not undergo bone scans?
Pregnant women and nursing mothers should not undergo bone scans as radiation exposure may harm the foetus and contaminate breast milk.
What are the risks and complications of a bone scan?
A bone scan carries the same risk level as conventional X-rays. The tracers used in a bone scan produce little radiation exposure. Almost all of it will be released from your body within 2 – 3 days. The risk of having an allergic reaction to the tracers is low.
How do you prepare for a bone scan?
Usually there are no special preparations or diet restrictions required for a bone scan, but your doctor will confirm this with you.
Do inform your doctor about the medications that you are taking, as some medicines can affect test results.
What can you expect in a bone scan?
In general, a bone scan is a painless procedure performed in an outpatient clinic.
Estimated duration
The injection and scan take approximately 1 hour altogether, but you may be asked to wait for 2 – 4 hours in between.
Before the procedure
You will be asked to remove all jewellery with metal, including body piercings.
During the procedure
A specialist will inject the tracer into your body through a vein in your arm. You will then be asked to wait for 2 – 4 hours to allow the tracer to move through your body. While waiting, you will be encouraged to drink plenty of water. This will help to flush out the radioactive material not collecting in your bones.
You will not be expected to isolate yourself as the amount of radioactivity in your body is safe for others to be near you.
Once the doctor determines that you are ready to proceed with the scan, you will be asked to lie still on a table while a tracer-sensitive camera passes back and forth over your body.
The scan itself can take up to an hour. The procedure is painless, but you may feel uncomfortable from having to stay in the same position for a long time.
After the procedure
In some cases, the doctor may ask you to return for further bone scans 3 – 5 hours after the first. This is to collect images taken at different intervals after the injection.
A radiologist will review your scan results and look for evidence of abnormal bone metabolism. These areas appear as darker "hot spots" and lighter "cold spots" where the tracers have or haven't been absorbed.
Although a bone scan is very sensitive to abnormalities in bone metabolism, your doctor may need to order other types of tests to fully diagnose your condition.
Care and recovery after a bone scan
As you should not feel any side effects from the tracer or the bone scan itself, you can resume normal activities after the scan. It is also safe to drive immediately after your scan.
You should continue drinking plenty of water for the next 1 – 2 days to flush out the remaining tracer in your body. Typically, all of it should be washed away after 2 days.
Contact your doctor right immediately if you have pain, redness, or swelling around the injection site on your arm.
