Concerning the occupational exposure in magnetic resonance imaging (MRI) facilities, the worker behavior in the magnetic resonance (MR) room is of such particular importance that there is the need for a simple but reliable method to alert the worker of the highest magnetic field exposure. Here, we describe a quantitative analysis of occupational exposure in different MRI working environments: in particular, we present a field measurement method integrated with a software tool for an accurate mapping of the fringe field in the proximity of the magnetic resonance bore. Three illustrative assessment studies are finally presented, compared and discussed, considering an example of a realistic path followed by an MRI worker during the daily procedure. The results show that the basic restrictions set by ICNIRP can be exceeded during standard procedure even in 1.5 T scanners. Using the described simplified metrics, it is possible to introduce behavioral rules on how to move around an MRI room that could be more useful than a numerical limit to aid magnetic field risk mitigation strategies.
Keywords: electromagnetic fields; exposure assessment; magnetic resonance; magnetic resonance imaging; occupational exposure.
© The Author(s) 2019. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.