A bone scan is a diagnostic study that uses a traceable radioactive substance to view your bone structure. It is used to assess areas of damage, cancer, infection and trauma.
The radioactive tracer is injected into the blood stream and accumulates in the bone, where it is detected by a special camera. Certain areas may appear brighter due to increased accumulation of the tracer. These are referred to as hot spots and represent increased activity and repair either due to a fracture, cancer, arthritis or infection. Some areas called “cold spots” appear darker due to less tracer absorption and may represent lack of blood supply or certain types of cancer.
A bone scan may be indicated to diagnose unexplained bone pain such as low back pain, cancer that has spread to the bone from other areas, conditions not clear on an X-ray and areas of bone damage caused by certain diseases. You should not undergo this test if you are pregnant or have recently had an X-ray using barium as a contrast material.
To perform a bone scan, first the tracer is injected, which may be painless or cause a stinging or pinching sensation. You will usually have to wait 1-3 hours to allow the tracer to accumulate in the bones before the scan is performed. Just before the scan, you are asked to drink fluids and empty your bladder to remove any tracer that has not been taken up by the bones. You will lie on a table and a special camera moves around your body to detect radiation released from the tracer and create images of the bones. You may be asked to shift your position to obtain other views. It is necessary to remain still during the procedure for accurate results. The entire procedure may take an hour to perform.
The radiation risks are negligible due to the minimal amount of radiation used. Other risks such as allergy to the tracer or swelling or soreness at the injection site may occur but are rare.