title: The effects of nuclear magnetic resonance imaging on ocular tissues.
abstract: Nuclear magnetic resonance, an imaging technique with great promise for detecting cerebral abnormalities, was studied to determine its possible deleterious effects on the mammalian eye. Young (3.5-week-old) Columbia-Sherman rats were exposed simultaneously to a constant magnetic field of 2.7 tesla and radio frequency pulses of 29 MHz at 800-ms intervals for six hours at field strengths representing the maximum used in a clinical setting. The six-hour exposure is many times greater than the four to six minutes currently employed in most diagnostic protocols. The animals were examined by slit-lamp biomicroscopy and ophthalmoscopy at regular intervals. Autoradiograms of lenses from animals injected with tritiated thymidine prior to exposure did not reveal any disturbances in cell-cycle kinetics. Eyes from rats not previously injected with the isotope were processed for cytopathologic analysis at various intervals. A two-year follow-up has indicated that at both the slit-lamp biomicroscopic and the light microscopic levels, there were no discernable effects on the rat eye.
mesh_terms: D000818:Animals; D001345:Autoradiography; D002453:Cell Cycle; D005123:Eye / Q000473:pathology*; D005260:Female; D007908:Lens, Crystalline / Q000473:pathology; D009682:Magnetic Resonance Spectroscopy / Q000009:adverse effects*; D008280:Magnetics; D051381:Rats; D011919:Rats, Inbred Strains; D013997:Time Factors