A bone scan is a medical imaging test that doctors use to identify areas of a patient’s bones with abnormal rates of bone metabolism. Physicians use bone scans with abnormal results to help them diagnose different medical conditions.
According to the U.S. National Library of Medicine, a patient has a radioactive tracer substance injected into his bloodstream and a camera scans the patient’s bones a few hours later.
A bone scan image with normal results shows the same shade of grey in all of a patient’s bones, according to Drugs.com. Normal results indicate an even absorption level of the tracer substance in all of a patient’s bones.
Abnormal bone scans may include black coloured or "hot" areas of bone with higher than normal absorption of the tracer substance and white or light coloured or "cold" areas of bone with below normal levels of tracer accumulation, according to Drugs.com.
Doctors may use abnormal bone scan results to help diagnose conditions such as bone tumours, bone fractures or degenerative bone diseases, according to the U.S. National Library of Medicine.
Physicians may conduct tests such as a biopsy of a bone area that showed abnormal bone scan results or additional imaging tests such as a magnetic resonance imaging test or a computerised tomography test to confirm a diagnosis of a medical condition, according to the Mayo Clinic.