1650c Prevention of electromagnetic exposure of workers near mri scanners – 25 years of experience in poland

Abstract

Introduction Inside the diagnostic chamber of magnetic resonance imaging (MRI) scanners, every worker (medical personnel, cleaners, administrative, etc.) is affected by the strong static magnetic field (SMF) emitted continuously by superconducting magnets (24 hours per day). Methods A retrospective study on the variety of parameters characterising the static and dynamic influence of SMF (B-field level and spatial distribution, spatial gradients (dB/dx), dynamic changes of exposure caused by body movements (dB/dt)) covered their analysis based on the results of our 25-year-long investigations into the context of the development of scanner design, work practice, requirements of occupational legislation and an understanding of the nature of health and safety hazards. Results We found significant variability in the exposure pattern, and that exposure parameters may not be proportional to the magnet power, but may be highly dependent on the scanner design. It suggests the potential to reduce worker exposure by ergonomic and organisational interventions. Conclusion Our extensive studies on workers’ SMF exposure near MRI scanners has shown that the set of SMF action levels (0.5, 3, 50, 200, 400 mT; 1, 2, 8T) may sufficiently characterise various hazards caused by the static and dynamic influence of SMF on workers and various objects. The three-dimensional mapping of SMF distribution near MRI magnets, and its graphical representation in the diagnostic room, provides significant practical information for managers and workers in the MRI centre, leading to an understanding of how to develop the work practice in order to reduce daily exposure to SMF. Research supported in Poland by the Ministry of Family, Labour and Social Policy – the National Programme ‘Improvement of safety and working conditions’ (project 1 .G.12).