Occupational exposure levels of static magnetic field during routine MRI examination in 3T MR system

Bioelectromagnetics. 2014 Jan;35(1):70-5. doi: 10.1002/bem.21817. Epub 2013 Sep 30.


Occupational exposure to the high static magnetic fields (SMFs) during magnetic resonance imaging (MRI) examinations raises concerns of adverse health effects. In this study, personal exposure monitoring of the magnetic fields during routine examinations in two 3 T MRI systems was carried out. A three-axis Hall magnetometer was attached to a subject's chest during monitoring. Data acquisition started every time the subject entered the scanner room and ended when the subject exited the room. Four radiologic technologists from two different institutes participated in this study. The maximum exposed field ranged from 0 to 1250 mT and the average peak magnetic field (B) was 428 ± 231 mT (mean ± standard deviation (SD): number of samples (N) = 103). Then, the relationship between exposure levels and work duties was analyzed. The MRI examination of the head or neck showed the highest average peak B among four work categories. These results provide information of real exposure levels for 3 T MRI system operators and can also improve the current practical training advice for preventing extra occupational field exposure.

Keywords: 3 T MRI system; personal exposure monitoring; static magnetic field.

Publication types

  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Female
  • Humans
  • Magnetic Fields / adverse effects*
  • Magnetic Resonance Imaging / adverse effects*
  • Magnetic Resonance Imaging / instrumentation
  • Male
  • Occupational Exposure*
  • Radiation Dosage
  • Radiation Monitoring