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What is a bone scan?

A bone scan looks for changes or abnormal areas in the bones.  You have the scan in the medical physics department, nuclear medicine department, or X-ray department of the hospital.

The radiographer injects a small amount of radioactive substance into your bloodstream. You wait for 4 hours and can eat and drink normally. During this time the substance travels through the blood and collects in the bones.

You then have the scan. You lie on an X-ray couch and a gamma camera takes pictures of the bones for about an hour. It can show where bone cells are being made or are breaking down. This can be a sign of cancer or other bone conditions.

Possible risks

The radioactivity in the injection is very mild and will not harm you. Your body gets rid of it in your urine over the following 24 hours. During this time you need to avoid close contact with pregnant women, babies and children.  If you think you might be pregnant tell your doctor before you have the test.

The results

It usually takes a couple of weeks to get the results. Contact your doctor if you haven’t heard anything after this time.


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How a bone scanner works

A bone scan looks for changes or abnormalities in the bones. It is also called a radionuclide scan, or a scintigram. You usually have it in the medical physics department, nuclear medicine department, or X-ray department of the hospital. A bone scan can look at a particular joint or bone. In cancer diagnosis, it is more usual to scan the whole body. The scan involves one injection but, apart from that, it is painless.

The scan uses a large camera called a gamma camera. Gamma cameras pick up radioactivity. To have the scan, you first have a radioactive substance called a radionuclide injected into your bloodstream. You only need a very small amount of this radioactive substance – not enough to do you any harm. The radionuclide travels through the blood and collects in your bones. It tends to collect more in areas where there is a lot of activity in the bone. Activity means the bone is breaking down, or repairing itself. These areas of activity are picked out by the camera. Doctors call them hot spots. They show up as dark areas (hot spots) on the scan. Below is an example of a bone scan.

A bone scan

Hot spots can be due to cancer in the bones, but they can also be caused by other medical conditions. Bone can break down and repair for different reasons. For example, if you have arthritis or an old fracture this may also show up on the scan.


Having the scan

You have the scan in either the medical physics department, nuclear medicine department or X-ray department at the hospital. You will have to arrive up to 4 hours before your scan to allow for the radionuclide to travel throughout your body and collect in the bones. The staff at the hospital or clinic will tell you beforehand exactly when you need to arrive.

When you arrive, you have the injection of radionuclide into a vein. Before you have this, the nurse or radiographer will ask you about allergies or asthma as some people can be allergic to it. The injection may make you feel hot and flushed for a minute or two. After the injection you will be free to leave the department for a couple of hours. The doctor will tell you exactly when you have to be back. You can walk around or sit down – what you do won't affect the scan.

The doctor will ask you to drink plenty of fluids while you are away. It doesn't really matter what you drink – you just need to flush the injection through your body. The doctor will ask you to pass urine just before you return (or when you return) to get rid of any radionuclide in your bladder. Otherwise this could interfere with the scan.

When you go back to the department, you usually go straight into the scanning room. You may have to undress and put on a hospital gown first, but this isn't always necessary.

When you are ready for the scan, you will lie down on an X-ray couch and will need to keep still. The gamma camera then takes pictures of the whole of your skeleton. Your body goes through the scanner. This makes some people feel claustrophobic, so let your doctor or nurse know if you feel nervous as they can help to reassure you. The scan takes about an hour.

Photograph of a bone scanner

After the scan, you will be free to go home. It can take up to 24 hours for the radionuclide to get out of your system. It will help if you drink plenty of fluids during this time.


Preparation for the scan

There are no special preparations for a bone scan. You don't have to restrict what you eat or drink.


Possible risks from a bone scan

A radioactive injection does sound dangerous, but you will only have a small amount of radioactivity given to you. It is about the same as 200 normal X-rays. This sounds a lot, but is not enough to be dangerous to you. The body gets rid of the radionuclide in the urine. This takes up to 24 hours. If you need to take any precautions in the meantime, the doctor or nurses will tell you beforehand.

These days, some doctors tell bone scan patients that they should not have close contact with pregnant women, babies and young children until the day after their scan. Breast feeding mothers are advised to express enough milk beforehand to get their baby through the first 6 hours after the scan. This isn't because there will be radiation in the milk. It is because the mother shouldn't be holding the baby that close during the time the radiation is in her body. Some doctors recommend you get someone else to feed the baby for 24 hours, although it is safe for you to express more milk for those feeds from 6 hours after your scan.

If there is a possibility you might be pregnant, you may not be able to have a bone scan. This is because the radionuclide could cross the placenta and affect the baby.


The results

It can take time for test results to come through. How long will depend on why you are having the scan but it may be a couple of weeks. Usually, a specialist in radiology or nuclear medicine examines the scan and a report is typed up. The report is then sent to your specialist, who gives the results to you. If your GP has sent you for the test, the results will be sent directly to the surgery.

Understandably, waiting for results can make you anxious. If your doctor needed the results urgently, it would have been noted on the scan request form and the results will be ready sooner than that. Try to remember to ask your doctor how long you should expect to wait for the results when you are first asked to go for the test. If it is not an emergency, and you have not heard a couple of weeks after your test, ring your doctor's secretary to check if they are back.

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Updated: 12 September 2013