Bone Scan
Key points
- A bone scan uses radiation to produce images showing areas of bone where the cells are unusually active.
- A bone scan commonly is used to check the skeleton for signs that cancer has spread (metastasized) to the bones from a primary (original) site located somewhere else in the body, such as the breast or prostate.
- Since the levels of radiation used in a bone scan can cause problems in an unborn child, tell your doctor if you are pregnant or if there is a possibility that you might be pregnant.
- Usually, a bone scan is an outpatient test, conducted in a test facility or hospital.
What Is It?
A bone scan uses radiation to produce images showing areas of bone where the cells are unusually active. Unusually active cells can indicate cancer, bone trauma, infection or degenerative disorders.
First, a radioactive chemical called an isotope is injected into a vein. The isotope enters the bloodstream and travels to the bones, where it emits gamma rays, which are similar to X-rays. A gamma camera can detect gamma rays. A computer analyzes the rays and forms an image (or scan) of the bones. Potential problem areas emit more intense rays and appear as bright spots on the scan.
A bone scan is painless, except for a mild skin prick to inject the isotope. It takes about three hours for the isotope to travel to the bones. During this time, you usually can leave the facility and return for the scan later, which generally takes about an hour.
What It's Used For
A bone scan commonly is used to check the skeleton for signs that cancer has spread (metastasized) to the bones from a primary (original) site located somewhere else in the body, such as the breast or prostate. Bone scans also can check for cancers that originate in the bones themselves. Bone scans also can check for noncancerous problems, including infections of the bones or joints and bone fractures that may be hidden or not easily diagnosed.
Preparation
Since the levels of radiation used in a bone scan can cause problems in an unborn child, tell your doctor if you are pregnant or if there is a possibility that you might be pregnant.
Before your bone scan, you will need to drink several glasses of water to help flush the isotope through your body. You also will need to empty your bladder before scanning starts. This helps produce clearer pictures.
How It's Done
Usually, a bone scan is an outpatient test, conducted in a test facility or hospital. The isotope will be injected into one of your veins, usually in your arm. Because it takes about three hours for the isotope to travel to your bones, many test centers allow patients to leave for a couple of hours and return later. When you return, you will lie in various positions on a table while the gamma camera scans your body. After the procedure, you can resume your normal activities.
Follow-Up
Results of your bone scan usually will be available in a day or two. Ask when you should call your doctor for the official report.
Risks
Written and revised by
Gerald Hurowitz, M.D.
Our doctors write and review articles for accuracy and keep them up to date.
health.am provides general information, not medical advice. Always consult a qualified health professional about your own health.