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Does assessment of personal exposure matter during experimental neurocognitive testing in MRI‐related magnetic fields?
Author(s) -
Nierop Lotte E.,
Christopherde Vries Yvette,
Slottje Pauline,
Kromhout Hans
Publication year - 2015
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.25173
Subject(s) - magnetostatics , neurocognitive , magnetic field , sensitivity (control systems) , magnetic resonance imaging , occupational exposure , bisection , computer science , nuclear magnetic resonance , mathematics , physics , psychology , medicine , cognition , radiology , neuroscience , quantum mechanics , electronic engineering , medical emergency , engineering , geometry
Purpose To determine whether the use of quantitative personal exposure measurements in experimental research would result in better estimates of the associations between static and time‐varying magnetic field exposure and neurocognitive test performance than when exposure categories were based solely on distance to the magnetic field source. Methods In our original analysis, based on distance to the magnet of a 7 T MRI scanner, an effect of exposure to static magnetic fields was observed. We performed a sensitivity analysis of test performance on a reaction task and line bisection task with different exposure measures that were derived from personal real‐time measurements. Results The exposure measures were highly comparable, and almost all models resulted in significant associations between exposure to time‐varying magnetic fields within a static magnetic field and performance on a reaction and line bisection task. Conclusion In a controlled experimental setup, distance to the bore is a good proxy for personal exposure when placing subjects at fixed positions with standardized head movements in the magnetic stray fields of a 7 T MRI. Use of a magnetic field dosimeter is, however, important for estimating quantitative exposure response associations. Magn Reson Med 73:765–772, 2015. © 2014 Wiley Periodicals, Inc.