An Overview of Electromagnetic Safety Considerations Associated with Magnetic Resonance Imaging

The introduction of magnetic resonance imaging into the clinical patient care arena has enabled a marked expansion of the diagnostic capabilities of the radiologist. The field has continued to grow each year with significant improvements and advances in such areas as transmitter/receiver coil design, pulse sequence design and optimization, and technical advances in other MR-related hardware devices. This rapid growth, however, has not been accompanied by an equivalent dissemination and understanding of the potential, or real, safety considerations that might be associated with this modality. Although most who work in this environment are aware of the potential interactions between the magnetic field of the imaging system and ferromagnetic objects, there seems to be a relative lack of understanding of some of the other safety issues associated with the imaging environment and function of a magnetic resonance imaging system. The recent renewed awakening of public interest in safety considerations of electromagnetic fields in general and the recent appearance of several comprehensive MR safety review have increased the timeliness of such a safety overview regarding electromagnetic and magnetic fields associated with magnetic resonance imaging, angiographic, and spectroscopic systems. Clinical magnetic resonance imaging, as it is presently practiced, is associated with several types of potential health concerns that impact both the patient as well as the health practitioners themselves that work in and around this environment. These can be classified and subdivided into several major areas, with varying degrees of importance depending upon such issues as field strength, magnet design, etc. The more common issues include the following: