A bone scan is a nuclear medicine imaging test that shows areas of increased or unusual bone activity. Instead of only showing the shape of a bone, it helps doctors look for places where the bone is repairing, inflamed, infected, injured, or affected by disease.
This is why a bone scan is often used when symptoms are present but the answer is not obvious on a regular X-ray.
Why might my doctor request a bone scan?
Your doctor may request a bone scan to:
- Investigate unexplained bone pain
- Check for bone infection
- Look for stress injuries or fractures that may not be obvious on an X-ray
- Assess whether cancer may have spread to the bones
- Help evaluate certain bone diseases or abnormal bone activity
It is commonly used in both adults and children, though the reason for the scan may differ by age group.
What does a bone scan show?
A bone scan shows areas where the tracer collects more than expected. These are sometimes called "hot spots."
Hot spots do not automatically mean cancer. They can also be caused by:
- Fractures
- Infection
- Arthritis
- Bone healing
- Other bone conditions
The scan is very good at showing that something is active in a bone, but it does not always explain the exact cause by itself. That is why doctors may interpret it alongside X-rays, CT, MRI, blood tests, or your symptoms.
How is the tracer given?
For a bone scan, the tracer is usually injected into a vein in your arm or hand.
After the injection, there is a waiting period so the tracer can circulate and collect in the bones.
What happens during the test?
Most bone scans happen in stages:
- A Radiographer injects the tracer into a vein
- You wait while the tracer travels through your body
- You may be asked to drink water and empty your bladder
- You lie on a scan table while a special camera takes pictures
The scan itself is painless. The main requirements are patience and keeping still while the images are taken.
How long does a bone scan take?
The imaging part often takes about 30 to 60 minutes, but the full visit is usually longer because there is often a waiting period of a few hours between the injection and the scan.
Your center will tell you how long to expect the appointment to last.
Do I need to prepare for a bone scan?
In many cases, no major preparation is needed.
You can often eat and drink normally and take your usual medicines, unless your imaging center tells you otherwise. You may be asked to remove metal items such as belts or jewelry before imaging.
Because local instructions vary, it is best to follow the preparation advice from the center doing your scan.
Will the scan hurt?
The scan itself does not hurt. You may feel a brief sting from the injection, and lying still for imaging may be a little uncomfortable if you already have bone pain.
What should I do after a bone scan?
Many patients are advised to drink extra water after the test to help flush the remaining tracer from the body. In most cases, you can return to normal activity the same day.
Depending on the tracer and local policy, you may be given short-term advice about limiting very close contact with babies or pregnant people for a period after the scan.
Is a bone scan safe?
For most people, yes. The amount of radioactive tracer used is small and chosen carefully for diagnostic purposes.
The scan is generally well tolerated, and side effects are uncommon. The main risks are usually limited to a minor injection-site bruise or, rarely, tracer-related reactions.
Can children have a bone scan?
Yes. Children can have bone scans when needed. Pediatric doses are adjusted carefully, and the scan can be useful in evaluating infection, injury, inflammation, or some bone disorders in younger patients.
What about pregnancy or breastfeeding?
Tell your imaging team before the scan if you are pregnant, think you might be pregnant, or are breastfeeding.
This is important because scan planning and aftercare advice can change depending on the tracer used and your situation.
When will I get the results?
A radiologist or nuclear medicine physician reviews the images and sends a report to the doctor who requested the scan. Your own doctor will explain the result and whether any other tests or follow-up are needed.
Is a bone scan the same as a DEXA scan?
No. They are different tests.
- A bone scan looks for abnormal bone activity.
- A DEXA scan measures bone density and is commonly used to assess osteoporosis.
They are used for different questions.
What are the important limitations and safety checks?
Nuclear medicine shows physiology and tracer uptake, but uptake is not always specific to one disease and spatial detail may be lower than CT or MRI. Inflammation, infection, treatment effects, medicines, blood glucose, recent imaging, movement, and the timing of images can change a result. A normal scan does not exclude every abnormality, and an abnormal focus may need correlation with CT, MRI, ultrasound, laboratory tests, biopsy, or follow-up imaging.
Preparation and radiation precautions are radiopharmaceutical- and protocol-specific. Tell the department before the tracer is given if you are or may be pregnant, are breastfeeding, care for a young child, or recently had another nuclear-medicine test. Do not stop medicines, fast, interrupt breastfeeding, or follow a fixed distancing period based only on a general webpage; obtain written instructions for the exact tracer, activity, and examination from the nuclear-medicine team.
Sources and further reading
- RadiologyInfo.org: General nuclear medicine
- RadiologyInfo.org: Preparing for a nuclear-medicine examination
- IAEA: Basics of quality management for nuclear medicine practices
Conclusion
A bone scan is a useful, patient-friendly way to look for active changes in the bones. It is especially helpful when doctors need to know whether pain, infection, fracture, or cancer-related bone involvement may be present, even when earlier tests have not given a complete answer.