Safety of human MRI at static fields above the FDA 8 T guideline: sodium imaging at 9.4 T does not affect vital signs or cognitive ability

PURPOSE: To assess whether exposure to a 9.4 T static magnetic field during sodium imaging at 105.92 MHz affects human vital signs and cognitive function. MATERIALS AND METHODS: Measurements of human vital signs and cognitive ability made before and after exposure to a 9.4 T MR scanner and a mock scanner with no magnetic field are compared using a protocol approved by the U.S. Food and Drug Administration (FDA). RESULTS: Exposure to a 9.4 T static magnetic field during sodium imaging did not result in a statistically significant change in the vital signs or cognitive ability of healthy normal volunteers. CONCLUSION: Vital sign and cognitive ability measurements made before and after sodium imaging at 9.4 T suggest that performing human MRI at 105.92 MHz in a 9.4 T static magnetic field does not pose a health risk.