Bone Scan

A bone scan is a nuclear scanning test used to identify new areas of bone growth or breakdown.  It can be done to evaluate damage to the bones, detect cancer that has metastasized to the bones, and to observe conditions that can affect the bones including infection and trauma.  A bone scan can detect a problem days to months earlier than a regular X-ray test.

For a bone scan, a radioactive tracer--commonly used in nuclear medicine studies--is injected into a vein in your arm.  The tracer substance travels through your bloodstream and into the bones. Areas that absorb little or no amount of tracer appear as dark spots, which may indicate a lack of blood supply to the bone known as a bone infarction, or the presence of certain types of cancer.  Areas of increased bone growth or repair absorb greater amounts of the tracer and present as bright spots in the pictures.  Bright spots may indicate the presence of a tumor, a fracture, or an infection.

A bone scan may be done on the entire body or just a part of it.

A bone scan is done to:

• Determine whether a cancer from another area, such as the breast, lung, kidney, thyroid gland, or prostate gland has spread or metastasized to the bone.
• Help diagnose the cause or location of unexplained bone pain, such as ongoing low back pain. A bone scan may be done initially to help determine the location of an abnormal bone in complex bone structures such as the foot or spine. Follow-up evaluation then may be done with a computed tomography (CT) or magnetic resonance imaging (MRI) scan.
• Help diagnose broken bones, such as a hip fracture or a stress fractures, not clearly seen on X-ray.
• Detect damage to the bones caused by infection or other conditions, such as Padget’s disease.

Before the bone scan, tell your doctor if:

• You are or might be pregnant.
• You are breast-feeding. Use formula and discard your breast milk for 1 to 2 days after the scan until the radioactive tracer has been eliminated from your body.
• Within the past 4 days, you have had an X-ray test using barium contrast material such as a barium enema or have taken a medication such as Pepto-Bismol that contains bismuth. Barium and bismuth can interfere with test results.

You may wish to limit your fluids for up to 4 hours before the test because you will be asked to drink extra fluids after the radioactive tracer is injected. You will empty your bladder right before the scan.

You usually have to wait 1 to 3 hours after the radioactive tracer is injected before your bone scan is done. Therefore, you may want to bring some reading materials or a project to pass the time during this waiting period. For some types of bone scans, pictures are taken during the tracer injection, immediately 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 you have regarding the need for the test, its risks, how it will be done, or what the results will indicate.