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Thresholds for perceiving metallic taste at high magnetic field
Ian D Cavin1, Paul M Glover, Richard W Bowtell
1Sir Peter Mansfield Magnetic Resonance Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, England, UK.
Journal of Magnetic Resonance Imaging : JMRI
|October 31, 2007
Summary
Moving near MRI scanners can cause a metallic taste, with 50% of people experiencing it during head movements. This effect, known as the metallic taste phenomenon, is linked to the rate of magnetic field change (dB/dt) and not dental fillings.
Area of Science:
- Medical Physics
- Neuroscience
- Sensory Science
Background:
- Workers near Magnetic Resonance Imaging (MRI) scanners sometimes report a metallic taste.
- The exact cause and threshold for this sensory phenomenon are not well understood.
Purpose of the Study:
- To characterize the metallic taste sensation experienced by individuals near a 7-Tesla MRI scanner.
- To identify the magnetic field parameters associated with this effect.
Main Methods:
- Twenty-one subjects performed controlled movements within the stray magnetic field of a 7-Tesla MRI scanner.
- Rates of magnetic flux change (dB/dt) were measured using a custom three-axis coil and data logger.
Main Results:
- Normal movements generated magnetic field changes up to 2 Tesla/second (T/s).
- Twelve out of 21 subjects detected a metallic taste, with significant individual variation in the threshold (minimum 1.3 T/s).
- The taste perception threshold was dependent on movement direction.
Conclusions:
- Approximately 50% of subjects are expected to perceive a metallic taste during head shaking (1.5s period, anterior-posterior field), corresponding to a dB/dt of 2.3 ± 0.3 T/s.
- The presence of dental fillings is not necessary for experiencing this metallic taste sensation.
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