Occupational exposure to static and time-varying gradient magnetic fields in MR units.

Purpose: To assess exposure of MR staff to static and time-varying gradient magnetic fields by direct measurement and questionnaire and to compare these to the action values and exposure limits stated in published guidance.

Materials And Methods: Instantaneous and time-averaged exposure to static magnetic fields were measured on clinical and research MR scanners. A questionnaire was sent to 100 clinical MR centers to estimate the average static field exposure.