Making the Diagnosis
The doctor may suspect osteomyelitis based on symptoms and a physical exam. A normal X-ray may not show anything until three weeks after the first symptoms appear. However, a bone scan called a radionucleide scan can often detect a bone infection in its early stages. In this procedure, small particles of radioactive material are injected into a vein and circulate in the blood throughout the body. Then a picture or scan is taken of the radioactive areas. If there are any abnormal areas, they will show up on the scan. The doctor may also order computerized tomography (CT) or magnetic resonance imaging (MRI) scans. These scans create three-dimensional visuals of the body, but they can't always differentiate a bone infection from other types of bone conditions.
Taking a sample of blood, pus, joint fluid, or the bone itself is the best way to make a diagnosis of osteomyelitis. If you have a bone infection in your spine, your doctor will check for signs of infection by taking a sample of fluid from the spinal vertebrae with a needle during a test or during bone surgery.