Hello, Welcome to Healthcaremagic. It is nothing but a bone scan. They will inject a radioactive substance into your arm through vein. This substance will travel into your body along with blood and into your bones. This may take several hours and finally special camera is used to scan the bones. Some areas in bones rapidly absorb the substance and some other areas little or not absorb the substance which depends upon the type of the disease. Some usual precautions are. You need not to be pregnant. You should not undergone any x ray procedure recently within 4 days. You must not breast feed. You must limit your water uptake before the procedure. Because you have to drink extra fluids after radioactive substance is injected during the procedure. this will help in clearing the radioactive substance from the body through urine. Just before the scan begins, you will probably be asked to empty your bladder to prevent any radioactive urine from blocking the view of your pelvic bones during the scan. Once inside your body, the Radioactive substance do not remain active for long. The radioactivity is mostly removed after one day and completely eliminated by two days. You should feel no side effects after the procedure, and no aftercare is necessary. Hope this helps. If you have additional questions or follow up queries then please do not hesitate in writing to us. I will be happy to answer your queries. Wishing you good health.