A bone scan is sometimes recommended to rule out the possibility of a tumor, infection or small fracture (called occult fractures because they cannot be seen on a x-ray) as the cause of chronic back pain. Radioactive fluid is injected through an intravenous line into the spine. The scanner in turn picks up on areas of the spine that are featuring new bone growth. New bone growth can indicate the presence of a fracture, infection or disease.
Bone scans do not detect the difference between a tumor, an infection or a fracture, only the presence of new bone growth, which can signify a problem. Therefore, this type of imaging study usually needs to be followed by a CAT scan or magnetic resonance scans (MRI scan) to identify the exact problem.