missile effectA term referring to the ability of an MRI scanner to dangerously attract ferromagnetic iron-based materials—which are core structural components of fire extinguisher, gas cylinders, carts, wheelchairs, floor polishers, gurneys and hospital beds—due to the MR scanner’s extremely high-strength magnets. The ferromagnetic nature of materials should be identified before being brought into the MRI suite, as all such ferromagnetic projectile incidents have the ability to cause injury.
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.
projectile effect(prŏ-jek′tĭl, ′tīl″) [L. projectilis, projecting]
The pulling of a ferromagnetic object (such as an oxygen cylinder, a respirator, or an IV pole) into the core of a magnetic resonance (MR) imaging device when the magnetic field is turned on. The effect can have disastrous consequences for patients and health care personnel. Objects drawn into the MR travel at faster and faster speeds as they near the magnetic field core, which surrounds the part of the patient being imaged.
CAUTION!To enhance safety, patients should have all watches, jewelry, coins, hair pins, paperclips, pens, credit cards, metallic articles of clothing, and other magnetically sensitive objects removed before they enter an MR imaging suite. It is especially important to determine whether a patient has any internal, magnetically sensitive foreign objects or prostheses.
Medical Dictionary, © 2009 Farlex and Partners