A bone scan involves injecting a very small amount of radioactive material (radiotracer) into a vein. The substance travels through your blood to the bones and organs. As it wears off, it gives off a little bit of radiation. This radiation is detected by a camera that slowly scans your body. The camera takes pictures of how much radiotracer collects in the bones.
If a bone scan is done to see if you have a bone infection, images may be taken shortly after the radioactive material is injected and again 3 to 4 hours later, when it has collected in the bones. This process is called a 3-phase bone scan.
To evaluate metastatic bone disease, images are taken only after the 3- to 4-hour delay.
The scanning part of the test will last about 1 hour. The scanner's camera may move above and around you. You may need to change positions.
You will probably be asked to drink extra water after you receive the radiotracer to keep the material from collecting in your bladder.