It does not use ionizing radiation and is seen as safer than imaging modalities that use x-rays, gamma rays, and positrons. However, the effects from the strong magnetic fields and radio frequency electromagnetic energy need to be considered. Some concerns are safety issues, others more of a nusiance. Credit cards can be erased if they get too close to the magnet. Most hospitals now have alternative equipment that is made of aluminum or other non-ferrous materials.
Vigilance is important when anyone enters the room.
You do not want to preceed someone into the room who may ave a pair of scissors in their pocket. It can become a lethal projectile in the room as you approach the magnet. Pacemakers may be affected by the electrical fields generated during imaging. NO ONE with a pacemaker should be allowed near the magnet. Other ferromagnetic or metallic objects - Patients should be screened carefully for prior surgeries where clips may have been used.