The word “bone” evokes a series of images fitting for an Edgar Allan Poe tale. It elicits tactile illusions of brittle, chalky, stone-like material. These are mere Hollywood fantasies.
Your bones aren’t like the fossilized pieces you see in museums. They are alive and teeming with activity. Living bones store and array of vital minerals and nutrients. Furthermore, the bone marrow (a flexible tissue inside some of your bones) is responsible for producing new blood cells.
When we reach adulthood, our bones continue to grow and renew themselves. Our body’s metabolic processes are constantly producing new bone material, either for the purpose of renewal or for the purpose of growth.
What is a Bone Scan?
The bone scan is the result of nuclear technologies being applied to the fields of medicine. Nuclear technologies have been playing a vital role in medical imaging since the x-ray was discovered in the late-1800s.
To conduct a bone scan, a radioactive substance (tracer) is injected into a vein. Once the substance reaches the bones, a special type of camera (gamma) is used to photograph the bones. This allows a physician to observe overall bone function.
When parts of the bone do not absorb the radioactive substance (or absorb only small amounts) the bone will appear to have dark or “cold” spots under the gamma. Cold spots typically indicate that parts of the bone are not getting enough blood supply. A lack of blood in the bone may be the result of infection or certain types of cancer.
When areas in the bone absorb large amounts of the radioactive substance, they will appear to be bright or “hot”. Hot spots are usually the result of fast-growing bone, which may indicate the presence of a fracture or tumor.
Bone scans are sometimes conducted in phases. For example, a scan might be performed while the radioactive tracer is being injected. Another scan might be performed shortly thereafter. And yet another scan might be performed hours after the injection. This will produce a more comprehensive image of the bone.
Why Would You Have a Bone Scan?
A physician will typically recommend a bone scan if they suspect the presence of any bone abnormalities. The scan will usually reveal any such abnormalities, which may include any of the following:
- Paget’s Disease of Bone or Osteitis Deformans: A disorder that causes the enlargement and/or deformation of the bones.
- Tumors: Tumors may or may not be cancerous.
- Various Infections
- Fibrous Dysplasia: A disorder that causes anomalous, scar-like tissue to develop on the bone.
- Avascular Necrosis: A disease that may temporarily or permanently inhibit blood from getting to the bones.
- Metastasis: Some cancers that arise elsewhere in the body may spread to the bones.
Bone Scan Risk Factors
Bone scans are about as harmful as common x-ray procedures. In other words, it’s a relatively painless procedure that poses near-negligible risks. Technically, a nuclear scan does introduce radioactive substances into the body, but the radiation exposure associated with a bone scan is minimal. Healthy cells are almost always able to withstand this sort of exposure.
Common risk factors and side effects may include:
Mild Discomfort: Injecting the radioactive substance into a vein may produce some slight pain and pressure. Any pain associated with a bone scan is the direct result of the tracer injection. It has nothing to do with “radiation”.
Lying Still: A full-body scan can take up to an hour. Lying still during the scan might be uncomfortable for some patients.
Pregnancy: Pregnant women are usually ineligible to receive a bone scan because their fetus may be unable to withstand the mild radiation exposure.
Bone Scan Preparation
You don’t need to do anything special to prepare for a bone scan. You can eat and drink as you please prior to the test. You might be asked to remove any jewelry, metal accessories, and/or other metal objects on the body before the scan.