Healthcare professionals working in magnetic resonance (MR) environments must be aware of warnings and contraindications for MRI examination and know requirements for careful initial patient screening, accurate determination, and characterization of permanent implanted or temporary devices. Medical devices and ferromagnetic objects may malfunction in a magnetic field or pose a projectile risk which could cause harm or injury to patients and staff. Controlling access to the environment and properly screening patients can help prevent accidents and injury. Only properly trained personnel are authorized to perform final patient screening and access equipment. Proper safety and security require plans for facility design and emergency preparedness.