MRIs(magnetic resonance imagery) is safe. It is not like a CT scan, which involves high doses of radiation. MRIs basically work by puling the protons in to alignment with a powerful magnet. The a radio wave is shot through the body to knock the protons out of alignment. Since the magnet is still on the protons get pulled back in to alignment. The computer takes the information of how long it takes for this to happen and uses this information to generate a 3D image. So no dangerous radiation involved.