What is a bone scan?
A bone scan is a specialized radiology procedure used to examine the various bones of the skeleton to identify areas of physical and chemical changes in bone. A bone scan may also be used to follow the progress of treatment of certain conditions.
A bone scan is a type of nuclear radiology procedure. This means that a tiny amount of a radioactive substance is used during the procedure to assist in the examination of the bones. The radioactive substance, called a radionuclide, or tracer, will collect within the bone tissue at spots of abnormal physical and chemical change.
The radionuclide emits a type of radiation, called gamma radiation. The gamma radiation is detected by a scanner, which processes the information into a picture of the bones.
The areas where the radionuclide collects are called "hot spots," and may indicate the presence of conditions such as malignant (cancerous) bone tumors, metastatic bone cancer (cancer which has spread from another site, such as the lungs), bone infections, bone trauma not seen on ordinary X-rays, and other conditions of the bone.
Reasons for the procedure
Bone scans are used primarily to detect the spread of metastatic cancer. Because cancer cells multiply rapidly, they will appear as a hot spot on a bone scan. This is due to the increased bone metabolism and bone repair in the area of the cancer cells. Bone scans may also be used to stage the cancer before and after treatment in order to assess the effectiveness of the treatment.
Other reasons for performing a bone scan procedure may include, but are not limited to, the following:
To assess for bone trauma in situations where ordinary X-rays do not reveal trauma
To detect fractures that are difficult to locate
To determine the age of fractures
To detect and/or assess bone infections (osteomyelitis)
To assess unexplained bone pain
To detect conditions such as arthritis, benign bone tumors, Paget's disease (a bone disorder, usually occurring in people over age 50, in which there is chronic inflammation of the bones, leading to thickening and softening of the bones, and curving of the long bones), and avascular necrosis (death of bone tissue not due to infection)
There may be other reasons for your doctor to recommend a bone scan.
Risks of the procedure
The amount of the radionuclide injected into your vein for the procedure is small enough that there is no need for precautions against radioactive exposure. The injection of the tracer may cause some slight discomfort. Allergic reactions to the tracer are rare, but may occur.
Patients who are allergic to or sensitive to medications, contrast dyes, or latex should notify their doctor.
If you are pregnant or suspect that you may be pregnant, you should notify your health care provider due to the risk of injury to the fetus from a bone scan. If you are lactating, or breastfeeding, you should notify your health care provider due to the risk of contaminating breast milk with the tracer.
There may be other risks depending on your specific medical condition. Be sure to discuss any concerns with your doctor prior to the procedure.
Before the procedure
Your doctor will explain the procedure to you and offer you the opportunity to ask questions that you might have about the procedure.
You may be asked to sign a consent form that gives your permission to do the test. Read the form carefully and ask questions if something is not clear.
Generally, no prior preparation, such as fasting or sedation, is required prior to a bone scan.
Notify the radiologist or technologist if you are allergic to or sensitive to medications, contrast dyes, or iodine.
If you are pregnant or suspect you may be pregnant, you should notify your health care provider.
Based on your medical condition, your doctor may request other specific preparation.
During the procedure
A bone scan may be performed on an outpatient basis or as part of your stay in a hospital. Procedures may vary depending on your condition and your doctor's practices.