Safety and magnetic resonance imaging

BMJ 1994;308:1181-1182 (7 May)

Editorials

Safety and magnetic resonance imaging

Magnetic resonance imaging entails a strong static magneticfield and changing magnetic and radiofrequency fields. Problemsarise from any metal objects present in the body.

With magnetic resonance imaging, the whole body is in the magneticfield, and sensitive organs cannot be "screened" - as they canin most techniques that use ionising radiation. For example,a foreign object in the head can interfere with the magneticresonance imaging of any part of the body, down to the toes,and the referring doctor and radiologist must be aware of anypotential source of interference even if it is physically distantfrom (and unrelated to) the problem being investigated. Cleaners,engineers, and anyone accompanying the patient during imagingare subject to the same risks: nobody known to harbour or suspectedof harbouring any hazardous object should come near the imager.The National Radiological Protection Board's arbitrary recommendationin 1983 that magnetic . . . [Full text of this article]