(MRI) a diagnostic imaging technique based on the emission of electromagnetic waves from the body when the patient is placed in a strong magnetic field and exposed to radiofrequency radiation (see nuclear magnetic resonance). The strength of the magnetic field is measured in teslas. Most images rely on the signal from hydrogen in water, which is particularly strong, although other elements can be used (see magnetic resonance spectroscopy). A major advantage over computerized tomography is the lack of X-rays, which reduces exposure to ionizing radiation. MRI is used for the noninvasive diagnosis and treatment planning of a wide range of diseases and also to guide interventional radiological procedures. See also functional magnetic resonance imaging.
Subjects: Science and Mathematics — Medicine and Health.