A bone scan is a special test useful in detecting fractures, infections, and different types of cancers. This test is ordered by your podiatrist or other physician to aid in diagnosis of a specific problem. The test is usually performed at the hospital or other radiography outpatient facility. This test differs in techniques and time required depending on the location and suspected diagnosis. Total body scans can be performed but typically in the foot and ankle a localized scan is done with one or both lower extremities only.
The procedure starts by a nuclear technologist injecting a radiotracer into a vein in your arm. It will feel like a pinprick as if you were having blood drawn. You should have no other effects of the test. This radiotracer will be passed through the bloodstream and eventually into your bones. The scan will detect where this tracer goes to. There maybe multiple scans taken during different phases of radiotracer uptake. For most scans you will lay on a table with the camera above or below you as the camera moves up or down your body slowly taking pictures. This process of a single scan can take from 30-60 minutes. The time between scans is usually 3-4 hours after the injection, but some can request a scan 24-48 hours after the injection as well for comparison. There is no special preparation needed for the scan. However, after the injection, you will be asked to drink plenty of fluids and to urinate as much as you need to help eliminate the tracer from the body tissue. This allows them to see the bones more clearly on the scans.
Bone scans are very safe. Your body is able to eliminate the radioactive material that is used very quickly. The dose of the radiation from this test is about 0.13 rem, which is about the same dose that you would get by having a routine x-ray of your foot.
The results will be sent to your podiatrist or physician that ordered the test directly. You will not recieve the results of your test the same day the procedure is performed as there is processing time and a radiologist proficient in nuclear medicine will have to examine the scans. What bone scans show are areas where the bone is undergoing changes. The test is very sensitive for bone abnormalities, but very non-specific to what the abnormality is. A comparison with routine x-rays may be helpful with diagnosis using bone scans, as well as history of injury or disease.
Results of your examination are not typically discussed with you at the time of the procedure. The technician assisting you will print the films and have the read by a radiologist. The results are then sent to your referring podiatrist. You may be requested to pick up your films at a later date to be taken to your Podiatrist. You can then set up an appointment with the podiatrist for discussion of the results from the MRI. Any bone undergoing change can cause a positive bone scan, which makes diagnosis even more difficult with scans. A child with an open growth plate will have a high uptake in that region, as well as any recent surgery on the bone due to the healing process. Results are often difficult and used only with a history and physical examination of the foot.