A bone scan is a test to help find the cause of your back pain. It can be done to find damage to the bones, find cancer that has spread to the bones, and watch problems such as infection and trauma to the bones. A bone scan can often find a problem days to months earlier than a regular X-ray test.
For a bone scan, a radioactive substance is injected into a vein in your arm. This substance, called a tracer, travels through your bloodstream and into your bones. This could take several hours.
A special camera takes pictures of the tracer in your bones. Areas that absorb little or no amount of tracer appear as dark or "cold" spots. This could show a lack of blood supply to the bone or certain types of cancer.
Areas of fast bone growth or repair absorb more tracer and show up as bright or "hot" spots in the pictures. Hot spots may point to problems such as arthritis, a tumor, a fracture, or an infection.
Why It Is Done
A bone scan is done to:
How To Prepare
Before the bone scan, tell your doctor if:
You may want to limit your fluids for up to 4 hours before the test, because you will be asked to drink extra fluids after the tracer is injected. You will empty your bladder right before the scan.
You probably will have to wait 1 to 3 hours after the tracer is injected before your bone scan is done. So you may want to bring something to read or a project to pass the time. For some types of bone scans, pictures are taken during the tracer injection, right afterward, and then 3 to 5 hours after the injection.
You may be asked to sign a consent form before the test. Talk to your doctor about any concerns or questions you have about the test.
How It Is Done
You will need to remove any jewelry that might get in the way of the scan. You may need to take off all or most of your clothes. You will be given a cloth or paper covering to use during the test.
Your arm will be cleaned where the tracer will be injected. A small amount of the tracer is injected.
It takes about 2 to 5 hours for the tracer to bind to your bone so that pictures can be taken with a special camera. During this time, you may be asked to drink 4 to 6 glasses of water so your body can wash out the tracer that does not collect in your bones. Just before the scan begins, you will probably be asked to empty your bladder to prevent any radioactive urine from blocking the view of your pelvic bones during the scan.
You will lie on your back on a table, and a large scanning camera will be above you. It may move slowly above and around your body, scanning for radiation released by the tracer and producing pictures. The camera does not produce any radiation.
You may be asked to move into different positions. You need to lie very still during each scan to avoid blurring the pictures.
A bone scan takes about 1 hour.
How It Feels
You may feel nothing at all from the needle when the tracer is injected, or you may feel a brief sting or pinch. The bone scan is usually painless. You may find it hard to remain still during the scan. Ask for a pillow or blanket to make yourself as comfortable as possible before the scan begins.
The test may be uncomfortable if you are having joint or bone pain. Try to relax by breathing slowly and deeply.
Allergic reactions to the tracer are rare. Your body will get rid of most of the tracer through your urine or stool within a day. Be sure to flush the toilet right away and thoroughly wash your hands with soap and water. The amount of radiation is so small that it is not a risk for people to come in contact with you after the test.
You may have some soreness or swelling where the needle went in. These symptoms can usually be relieved by applying moist, warm compresses to your arm.
There is always a slight risk of damage to cells or tissue from being exposed to any radiation, including the low level of radiation released by the tracer in this test.
The results of a bone scan are usually available within 2 days.
What Affects the Test
Reasons you may not be able to have the test or why the results may not be helpful include:
What To Think About
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