A bone scan uses small amounts of radioactive material (radiotracers) and a computer to produce an image of the skeleton. This image reveals changes or abnormalities in the bones. A bone scan is also called a skeletal scan.
Why do you need a bone scan?
Bone scans help doctors diagnose and assess different bone diseases and conditions. It can be used for:
find bone cancer or determine if cancer in another area has spread to the bones
help diagnose the cause or determine the location of unexplained bone pain;
help diagnose bone fractures that are not obvious on x-rays;
see how far the cancer has spread;
find bone damage caused by infection or other bone conditions;
find out if cancer treatment is working or for follow-up.
How the bone scan is performed
Bone scintigraphy is usually done in the nuclear medicine department of a hospital, on an outpatient basis. Usually, no special preparation is necessary. If you are breast-feeding or if you are pregnant, or think you may be, it is important to tell your doctor or nuclear medicine staff before having the test.
You will be asked to wear clothing without metal zippers, belts or buttons. You will also be asked to take off your glasses, jewelry, and all or most of your clothing. You will be given a paper or cloth hospital gown to wear during the test.
Your arm will be cleaned and injected with a small amount of a radiotracer. The radiotracer travels through the blood to bones and organs. It takes 3 to 4 hours for it to build up in your bones. During this time, you may be asked to drink 4 to 6 glasses of water to flush the radiotracer out of your body, which does not build up in your bones. You will also need to empty your bladder before the exam.
As it dissipates, the radiotracer emits some radiation which is detected by the camera which slowly travels around your body. This stage lasts approximately 1 hour. The camera can move above and around you while you are lying still. You may be asked to change your position. Pictures may be taken immediately after the injection and then another 3 to 4 hours later.
After the examination, the radiotracer quickly loses its effect. It is passed from the body through urine or stool (feces) during the first hours or days afterwards. The radiation dose is low (similar to that used for an x-ray). It is okay to come into contact with you after the exam.
You will be told what special precautions you should take after the exam. Drinking fluids helps flush the radiotracer out of the body. It is important to wash your hands thoroughly with soap and water after using the toilet. You might also be told to flush the toilet twice immediately afterwards.
Side effects of bone scan
The injection site may be sore or swollen. In very rare cases, there may be an allergic reaction to the radiotracer.
What the results mean?
A normal bone scan shows that the radiotracer has spread evenly through the bones, with no areas where too much or too little is present.
An abnormal bone scan reveals hot areas and cold areas.
Hot spots are areas of the bone where the radiotracer has accumulated. They can be caused by bone cancer, arthritis, infection, or bone disease.
Cold spots are areas of bone where there is no radiotracer. They can be caused by a certain type of cancer, such as multiple myeloma, or a lack of blood supply to the bone.
What happens if the results are abnormal
Your doctor may recommend additional tests, procedures, follow-up, or treatment.
Special considerations for children
Preparing a child for a test or procedure can reduce anxiety and increase collaboration, and help develop coping skills. Preparation includes explaining what will happen during the exam, including what they will see, feel and hear.
Children respond to tests and treatment differently depending on their age, stage of development (that is, how they behave and what they are able to understand) and their personality. Some children can become dependent and demanding. Others may turn in on themselves or express their frustrations with their parents or caregivers.
Prepare the child for tests or treatment
Talking to a child about the tests or treatment before they happen can help them prepare physically and mentally. Many families find it helpful to visit the room where the test or treatment will take place and to meet the people who will be performing the procedure. Encourage your child to ask questions and try to answer them as honestly and in as much detail as possible. When possible, tell your child the following:
- what he will hear, see, smell, experience or even taste during the test
- why he should take this test or receive this treatment
- who will perform the procedure
- where the test or treatment will take place
- what part of their body will be examined or treated
- how the test or treatment will be performed (including the equipment that will be used or the noises it will hear)
- each step of the intervention, if there is more than one
- what he will feel during the test or procedure (be as descriptive as possible)
- how long the test or treatment can last
Treat pain during testing and treatment
Some tests or treatments done in the presence of cancer can be unpleasant or painful. Being stressed about the test can make the pain worse. There are different ways you can treat your child’s pain or help them relax and stay calm during the test or treatment. The best ways to relieve pain or stress depend on the situation. Nonmedicinal methods are often combined with medicines to treat a child’s pain.
Stress can make the pain worse, so you can help your child just by talking to them about their stress or anxiety. Children are often stressed or scared long before a test or treatment. Preparing a child for a test or treatment should start well before they enter the exam room. Resources are available at the hospital to help you.
In some cases, you can treat the pain with physical, psychological, or complementary therapies.
Sedation or anesthesia may be used to control the pain or help the child stay calm during tests or treatment. During sedation, medicines are used to calm the child or help him sleep. Medicines are used during anesthesia to numb a part of the body (local anesthesia) or to cause unconsciousness (general anesthesia).