Acute neurobehavioral effects of exposure to static magnetic fields: analyses of exposure-response relations.

PURPOSE: To assess exposure-response relations between exposure to magnetic fields and neurobehavioral effects. MATERIALS AND METHODS: Twenty company volunteers completed a neurobehavioral test battery after they moved their heads with the magnetic field absent, and while they moved their heads in the inhomogenous stray fields of 1.5 and 3.0 T MRI magnets. RESULTS: The value of the stray fields at the position of the head of the volunteer was estimated to be 0.6 T and 1.0 T on the 1.5 T and 3.0 T systems, respectively. Exposure-response relations were found for visual (-2.1%/100 mT) and auditory (-1.0%/100 mT) working memory, eye-hand coordination speed (-1.0%/100 mT), and visual tracking tasks (-3.1%/100 mT). Eye-hand precision, scanning speed, and visual contrast sensitivity were apparently not influenced by the magnetic field strength. CONCLUSION: Additional research should focus on the potential side effects of interventional MR procedures because of the exposure to strong magnetic fields of these systems.