Vertigo Research Today is a free monthly online journal that collates and summarizes the latest research about Vertigo, including details on causes, symptoms, treatment, dizziness.

Biologic effects of 3 Tesla (T) MR imaging comparing traditional 1.5 T and 0.6 T in 1023 consecutive outpatients.

Weintraub MI, Khoury A, Cole SP

Department of Neurology and Medicine, New York Medical College, Valhalla, New York, USA. miwneuro@pol.net

BACKGROUND: The recent use of high and ultra-high magnetic field (MF) systems (3.0 T and above) have raised concerns about biologic effects and safety. Sensory symptoms (magnetophosphenes, dizziness/vertigo, headaches, metallic taste, pain changes, and cognitive effects) have been reported. We monitored 1023 consecutive outpatients undergoing MRI after recent introduction of a 3 T MR unit in our community. METHODS/DESIGN: Observational study utilizing a pretest and posttest symptom rating scale (0-10) questionnaire presented to subjects undergoing MRI at three different facilities with five MRI machines, specifically a 3 T (Philips), three units with 1.5 T (GE, GE, Philips), and one 0.6 T (Fonar) unit to record symptoms before and after study. RESULTS: 147 subjects (14%) experienced either new (N= 69; 6.7%) or changes (N= 78; 8%) in symptoms. New onset symptoms occurred predominantly with 3 T and female preponderance (75%) [P= .002]. Vertigo/dizziness (N= 28, 5.6%) [P= .001], headache (N= 8), spine pain (N= 11) occurred more frequently on 3 T, whereas magnetophosphenes (N= 8) and metallic mouth symptoms (N= 4) occurred principally in 1.5 T. Seventy-eight subjects (8%) experienced pain symptoms upward arrow downward arrow with 75% occurring with 1.5 T. Females were 60%. Forty-three percent of individuals had brain MRIs. Symptoms of vertigo/dizziness, headaches, and magnetophosphenes were more commonly seen in individuals undergoing brain MRIs but other body sites were also represented. CONCLUSIONS: Although no harmful effects were reported in 1023 cases, an unexpected high rate of 14% of individuals experienced sensory stimulation in both 3 T and 1.5 T units. Females appear to be more magnetically sensitive.

Published 4 July 2007 in J Neuroimaging, 17(3): 241-5.
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