Article Text

Download PDFPDF
Original article
Effects of magnetic stray fields from a 7 Tesla MRI scanner on neurocognition: a double-blind randomised crossover study
  1. Lotte E van Nierop1,
  2. Pauline Slottje1,
  3. Martine J E van Zandvoort2,
  4. Frank de Vocht3,
  5. Hans Kromhout1
  1. 1Division of Environmental Epidemiology, Institute for Risk Assessment Sciences, Utrecht University, Utrecht, The Netherlands
  2. 2Helmholz Institute, Utrecht University, Utrecht, The Netherlands
  3. 3Centre for Occupational and Environmental Health, School of Community Based Medicine, University of Manchester, Manchester, UK
  1. Correspondence to Professor Dr Hans Kromhout, Institute for Risk Assessment Sciences, Utrecht University, PO Box 80178, Utrecht 3508 TD, The Netherlands; h.kromhout{at}


Objective This study characterises neurocognitive domains that are affected by movement-induced time-varying magnetic fields (TVMF) within a static magnetic stray field (SMF) of a 7 Tesla (T) MRI scanner.

Methods Using a double-blind randomised crossover design, 31 healthy volunteers were tested in a sham (0 T), low (0.5 T) and high (1.0 T) SMF exposure condition. Standardised head movements were made before every neurocognitive task to induce TVMF.

Results Of the six tested neurocognitive domains, we demonstrated that attention and concentration were negatively affected when exposed to TVMF within an SMF (varying from 5.0% to 21.1% per Tesla exposure, p<0.05), particular in situations were high working memory performance was required. In addition, visuospatial orientation was affected after exposure (46.7% per Tesla exposure, p=0.05).

Conclusion Neurocognitive functioning is modulated when exposed to movement-induced TVMF within an SMF of a 7 T MRI scanner. Domains that were affected include attention/concentration and visuospatial orientation. Further studies are needed to better understand the mechanisms and possible practical safety and health implications of these acute neurocognitive effects.

  • MRI
  • static magnetic fields
  • static magnetic stray fields
  • time-varying magnetic fields
  • cognition
  • exposure
  • risk assessment
  • electromagnetic fields
  • occupational health practice
  • exposure assessment
  • statistics
  • hygiene/occupational hygiene
  • epidemiology
  • retrospective exposure assessment
  • neurobehavioural effects
  • longitudinal studies
  • exposure monitoring
  • bronchitis
  • health and safety
  • epidemiology

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.


  • Funding This work was supported by The Netherlands Organisation for Health Research (ZonMW) within the program Electromagnetic Fields and Health Research under grant numbers 85100001 and 85800001.

  • Competing interests None.

  • Ethics approval The study was approved by the local medical ethics committee (study number: 09-310) of University Medical Center Utrecht (UMCU), the Netherlands. Medical ethics committee of University Medical Center Utrecht (UMCU), the Netherlands (study number: 09-310).

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data sharing statement All authors had full access to all data and can take responsibility for the integrity of the data and the accuracy of the data analysis.