Medical Q&As

Bone scan - same as MRI?

I have to attend hospital for an isotope bone scan next week. Is this the same as an MRI or CAT scan? I have suffered a major soft tissue injury in my left foot. Will I have to go into a “cylinder-thingy”, or is the procedure simply the same as an ordinary X ray?

An isotope bone scan does not require that you be inserted into a “cylinder-thingy”. If you have fears of being enclosed in confined spaces you do not need to worry about that possibility with an isotope bone scan. Prior to the examination you will be given a small injection into an arm vein of a special radioactive chemical called an isotope. This chemical travels through the bloodstream and enters the bones. It takes a couple of hours for this process to take place and it is sometimes possible to leave the imaging department and return later for the actual scan. Once the isotope has reached the bones it emits gamma rays from the bones, which are detected by a special camera called a gamma camera. The rays are then analysed by a computer, which then formulates an image of the bones. If there are abnormal areas within the bones those areas will emit more rays, which will appear as bright spots on the scan. Gamma rays are in many ways similar to X rays and involve exposure to much less radiation than would occur with many conventional X ray examinations. The isotope is quickly excreted from the body in the urine within hours of the procedure taking place. Therefore there is no need for concern regarding possible radiation hazards. A bone scan is a painless procedure apart from the mild skin prick that occurs when injecting the isotope. The equipment used for the examination resembles conventional X ray apparatus and does not require enclosure of the person being examined.