open magnetic resonance imaging (open MRI), a procedure that allows visualization of soft-tissue structures of the body. Because the patient is not enclosed within the magnetic resonance unit, claustrophobic reactions do not occur with open magnetic resonance imaging, but the scan does take substantially longer to complete. As with traditional magnetic resonance imaging, patients must remain motionless, and images may be degraded by motions related to heart contractions, respiration, and bowel peristalsis. Contraindications to MRI are pacemakers, metallic aneurysm clips, and some metallic prostheses and foreign objects. Compare magnetic resonance imaging. See also magnetic resonance.
