Pilot study investigating the effect of the static magnetic field from a 9.4-T MRI on the vestibular system.
OBJECTIVE
To objectively evaluate workers' sensory symptoms and vestibular function after exposure to a strong, new generation 9.4-T Magnetic Resonance Imaging (MRI) scanner.


METHODS
Six MRI employees underwent standardized electronystagmographic evaluation, postural testing, and caloric function at baseline evaluation, 30 minutes postexposure to 9.4 T static field and at a 3-month follow-up.


RESULTS
All participants noted sensory symptoms after exposure. No overall deterioration in vestibular function was noted following 30-minute exposure or at a 3-month follow-up. A higher occurrence of tonic vestibular asymmetry, hyperreactive caloric responses, and spontaneous nystagmus was noted compared with that of the normal population.


CONCLUSIONS
Workers exposed to the new, stronger MRIs experience sensory symptoms but it is unclear as yet whether long-term vestibular damage occurs. The higher rates of vestibular changes noted could argue for improved worker surveillance and exposure control.
Patel
Mita
M
Division of Environmental and Occupational Health Sciences, Occupational Medicine Residency Training Program, University of Illinois, Chicago School of Public Health, Chicago, Illinois, USA. mitapatel77@yahoo.co.uk
Williamsom
Robert A
RA
Dorevitch
Samuel
S
Buchanan
Susan
S
D000328:Adult; D004574:Electromagnetic Fields / Q000009:adverse effects*; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D009759:Nystagmus, Pathologic / Q000209:etiology; D016273:Occupational Exposure / Q000009:adverse effects*; D010865:Pilot Projects; D011795:Surveys and Questionnaires; D015837:Vestibular Diseases / Q000209:etiology* / Q000503:physiopathology*; D014724:Vestibular Function Tests