What is a bone scan?
A nuclear medicine bone scan shows the effects of injury or disease (such as cancer) or infection on the bones. A nuclear medicine bone scan also shows whether there has been any improvement or deterioration in a bone abnormality after treatment.
A radioactive material (radiopharmaceutical) is injected into a vein, attaches to the bones and is detected by a special camera (gamma camera) that takes images or pictures that show how the bones are working.
Why would my doctor refer me to have this procedure?
Nuclear medicine bone scans are carried out for many different reasons.
Bone scans image both the structure and the active cell growth of the bones, so are often used in conjunction with other imaging e.g. X-rays, computed tomography (CT) or magnetic resonance imaging (MRI).
They are often used as a follow-up test when the cause of your pain or symptoms needs to be clarified, for example:
- to evaluate the source of bone pain; for example, foot or hip pain
- to evaluate the findings from other diagnostic images or abnormal laboratory results.
Listed below are some common reasons why your doctor may refer you for a bone scan:
- difficult to find fractures, stress fractures, shin splints
- osteomyelitis (infection of the bone), cellulitis (infection of the skin) or to assess a response to treatment (e.g. antibiotics) you might be having
- arthritis, Paget’s disease, fractures from osteoporosis (where bones become fragile and are more likely to break)
- to assess the presence or spread of cancer in bone, then to follow up on the response to treatment
- complex regional pain syndrome (CRPS or previously known as reflex sympathetic dystrophy), avascular necrosis, prosthesis loosening or infection.
How do I prepare for a bone scan?
There is no special preparation for a bone scan.
However, it is important to drink normally or more than usual, as the radiopharmaceutical is eliminated from your body in your urine. You should continue to take your usual medications.
You will need to lie still while the images are being taken, so they are not blurred. If you feel you will not be able to stay still for a long period of time, please advise your own doctor or the nuclear medicine staff where you are having the scan.
If you are severely claustrophobic, please advise the department when you make your appointment.
If you are (or think you might be) pregnant, breast-feeding and/or the primary or sole carer for small children, you must inform the doctor who is referring you for the bone scan and also the staff where you are having the bone scan.
Bone scans are generally not carried out on pregnant women.
Women who are breast-feeding and people who are the primary or sole carer for small children might need to make special preparations for after the scan. This will involve stopping breast-feeding and avoiding close contact with young children for a short time. This is due to the small amount of radioactivity your body might release after the scan injection. You should discuss this with your referring doctor or with the nuclear medicine practice where you will be having the test.
The Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) has recommendations about breast-feeding and close contact with children after nuclear medicine tests. For a bone scan, the recommended time for not breast-feeding or having close contact with young children is 1 hour. It might be easiest to breast-feed your baby immediately before the test. You might need a bottle of formula or previously expressed breast milk available. Someone else should care for the baby or any young children for the hour after the injection.
What happens during a bone scan?
There are two parts to a bone scan – an injection of radiopharmaceutical into a vein (sometimes accompanied by ‘early’ imaging) and then ‘delayed’ imaging between 1–4 hours later.
Part 1
You will receive an injection of a small amount of radiopharmaceutical into a vein. Sometimes images are taken with the gamma camera immediately after the injection to look at the blood flow to the area being scanned. These images are referred to as ‘early’ (blood flow or blood pool) imaging. Whether or not you have ‘early’ imaging will depend on why your doctor has requested the scan.
Part 2
After 2–4 hours for adults and 1–3 hours for children, you return to have the ‘delayed’ images. These images show how the bones are working. The reason for the length of time between the injection and the ‘delayed’ images is to give the radiopharmaceutical time to be absorbed into the bones.
Some specific images might need to be taken; that is, single-photon emission computed tomography (SPECT; images taken in 3-D showing the height, width and depth of the part of the body being scanned) or SPECT-CT (a combination of SPECT and CT), which can take slightly longer.
The radiopharmaceutical you receive for the bone scan is eliminated from your body through the urine. For that reason, you should drink plenty of fluids and urinate frequently after the injection. How much fluid will depend on each individual, but you should be well hydrated, and for an adult this could be three to four glasses of water. Your urine will not change colour. Your urine will contain the radioactive material, so it is recommended that you wash your hands well after going to the toilet.
In the case of babies and youngsters in nappies who are having a bone scan, there will be a small amount of radioactivity in the urine and therefore in the child’s nappy. The radioactive material will not affect the child’s skin, but carers should wash the child’s bottom and wash their own hands thoroughly. Cloth nappies need to be washed thoroughly and disposable nappies tied in a plastic bag before binning.
Are there any after effects of a bone scan?
Normally, there are no after effects of a nuclear medicine bone scan.
The radiopharmaceutical used in a bone scan is not known to have any adverse interaction with food or medication you might be taking. You should feel no effect from the injection of radiopharmaceutical. You can carry out normal activities between the injection and the delayed images, and after the scan.
If you are breast-feeding or caring for young children, see the ‘how do I prepare’ section for more information about special precautions you might need to take.
How long does a bone scan take?
There are two parts to a nuclear medicine bone scan. In the first part, you receive an injection into a vein in your arm that usually takes 15–30 minutes. This includes time to explain the procedure and take any ‘early’ images, if required.
In the second part, you return after 1–4 hours to have ‘delayed’ images taken. These can take between 15 and 60 minutes, depending on the area/s of interest and any specific images that that have been requested; for example, SPECT or SPECT-CT. Occasionally, the doctor will ask the patient to return for delayed images the next day, particularly if there is a need to see the hips or pelvis in patients who are unable to completely empty their bladder.
What are the risks of a bone scan?
There are minimal risks involved in the nuclear medicine bone scan procedure.
The scan involves a small dose of radiation from the radiopharmaceutical injected into your vein. See Radiation Risk of Medical Imaging for Adults and Children. The dose is similar to CT and fluoroscopy procedures.
If you are breast-feeding or caring for young children, see the ‘how do I prepare’ section for more information about special precautions you might need to take.
Rarely, allergic reactions have been associated with bone scan agents.
What are the benefits of a bone scan?
A bone scan helps your doctor evaluate how your bones are working, and provides information to help diagnose and treat your condition. It can show injury to the bones, the effects of disease such as cancer or infection, as well as any improvement or deterioration in a bone abnormality after any treatment you might be having.
Who does the bone scan?
The nuclear medicine bone scan is carried out by nuclear medicine technologists. The images taken by the technologist are reviewed by a nuclear medicine specialist doctor who provides a written report to the doctor who referred you for the bone scan.
Where is a bone scan done?
Most large public and private hospitals, and private radiology practices have nuclear medicine facilities where bone scans are carried out.
When can I expect the results of my bone scan?
The time that it takes your doctor to receive a written report on the test or procedure you have had will vary, depending on:
- the urgency with which the result is needed;
- the complexity of the examination;
- whether more information is needed from your doctor before the examination can be interpreted by the nuclear medicine specialist;
- whether you have had previous X-rays or other medical imaging procedures that need to be compared with this new test or procedure (this is commonly the case if you have a disease or condition that is being followed to assess your progress);
- how the report is conveyed from the practice or hospital to your doctor (i.e. phone, email, fax or mail).
Please feel free to ask the private practice, clinic or hospital where you are having your test or procedure when your doctor is likely to have the written report.
It is important that you discuss the results with the doctor who referred you, either in person or on the telephone, so that they can explain what the results mean for you.
