The AAPM/RSNA physics tutorial for residents. MR imaging safety considerations. Radiological Society of North America

Abstract

Experience and research over the past decade have demonstrated that diagnostic magnetic resonance (MR) imaging is a biologically safe imaging modality. Specifically, there is currently no convincing evidence that there is any long-term or irreversible biologic effects associated with the radiation and magnetic fields used in MR imaging, specifically radio-frequency (RF) radiation, static magnetic fields, and time-varying gradient fields. However, numerous hazards of MR imaging do exist that can cause severe injuries or even death. These hazards are primarily the result of (a) strong magnetic fields and the strong force that they exert on ferromagnetic objects brought into their influence, including interference with electronic devices such as pacemakers and other implanted electronic devices, and (b) RF burns resulting from inadvertently induced currents in conductive loops placed on the patient's skin surface (eg, electrocardiographic leads and other monitoring devices). Other potential concerns are peripheral nerve stimulation resulting from rapidly switched gradients and auditory noise levels. Establishing a complete and coordinated educational program for all MR imaging facility personnel and conducting effective screening and preparation of patients scheduled for MR imaging procedures are essential to avoid accidents and RF burns and to maintain a safe MR imaging facility.