Occupational Electromagnetic Fields exposure in Magnetic Resonance Imaging systems - Preliminary results for the RF harmonic content.

Physica medica : PM : an international journal devoted to the applications of physics to medicine and biology : official journal of the Italian Association of Biomedical Physics (AIFB) · 2015 · Mixed · Low evidence

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MixedLow evidencePaper 4784

Study snapshot

PublicationPhysica medica : PM : an international journal devoted to the applications of physics to medicine and biology : official journal of the Italian Association of Biomedical Physics (AIFB) · 2015

Study typeexposure_assessment

Reported directionMixed

Evidence ratingLow

Abstract

PURPOSE: European legislation concerning the protection of workers from exposure to Electromagnetic Fields (EMF) was recently (26.6.2013) completed by Directive 2013/35/ΕU. This Directive is a specific one of the framework Directive 89/391/EEC and part of the overall legislation for Occupational Health and Safety (OHS). Magnetic Resonance Imaging (MRI) systems have played a key role, both in the postponement of the former 2004/40 EMF Directive and in the formation of the latest limits adopted by the new Directive. On the other hand, MRI systems are associated with the exposure of personnel to EMF of various frequencies and modulations, arousing peculiar safety issues. Therefore, we will try to acquire the highly important knowledge of the exact occupational exposure levels, in all working scenarios and practices. METHODS: Different MRI systems (1.5 and 3 T) have been chosen for a variety of measurements in order to assess occupational exposure compared to the limits (ALs) of the Directive and to the main OHS principles. Gradient function of MRI systems results in low frequency exposure, while high frequency exposure comes from the application of the RF excitation frequency. RESULTS: In most of the cases the RMS and peak value measurements do not exceed the corresponding ALs, apart from a few specific hot spots, manageable through OHS principles. DISCUSSION: Complete occupational exposure results can form the basis for dealing with multiple exposures present in MRI systems. Peculiar RF harmonic components, of no safety concern, were detected. Their origin is under examination.

Machine Enhanced Logic

AI evidence extraction

Structured fields below were generated from the paper’s abstract and metadata to make the evidence easier to inspect. Automated extraction may be incomplete or incorrect; verify important details against the original paper.

Study typeexposure_assessment

Effect directionmixed

PopulationMRI personnel/workers (occupational exposure context)

Sample sizeNot supplied

ExposureRF

Evidence strengthLowConfidence: 74% · Peer reviewed: yes

Main findings

Measurements in 1.5 T and 3 T MRI systems found that in most cases RMS and peak exposure values did not exceed the corresponding Action Levels of Directive 2013/35/EU; a few specific hot spots exceeded or approached limits but were described as manageable through occupational health and safety principles. RF harmonic components were detected and described as of no safety concern, with their origin under examination.

Outcomes measured

Measured occupational EMF exposure levels in MRI environments (RMS and peak values)
Comparison of measured exposure to Action Levels (ALs) in EU Directive 2013/35/EU
Detection/characterization of RF harmonic components

Limitations

Preliminary results (as stated in title)
Sample size and measurement protocol details not provided in abstract
Quantitative exposure values and frequency details not reported in abstract
Hot spot locations/conditions not fully described in abstract

View raw extracted JSON

{
  "study_type": "exposure_assessment",
  "exposure": {
    "band": "RF",
    "source": "occupational",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": null
  },
  "population": "MRI personnel/workers (occupational exposure context)",
  "sample_size": null,
  "outcomes": [
    "Measured occupational EMF exposure levels in MRI environments (RMS and peak values)",
    "Comparison of measured exposure to Action Levels (ALs) in EU Directive 2013/35/EU",
    "Detection/characterization of RF harmonic components"
  ],
  "main_findings": "Measurements in 1.5 T and 3 T MRI systems found that in most cases RMS and peak exposure values did not exceed the corresponding Action Levels of Directive 2013/35/EU; a few specific hot spots exceeded or approached limits but were described as manageable through occupational health and safety principles. RF harmonic components were detected and described as of no safety concern, with their origin under examination.",
  "effect_direction": "mixed",
  "limitations": [
    "Preliminary results (as stated in title)",
    "Sample size and measurement protocol details not provided in abstract",
    "Quantitative exposure values and frequency details not reported in abstract",
    "Hot spot locations/conditions not fully described in abstract"
  ],
  "evidence_strength": "low",
  "confidence": 0.74,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "occupational exposure",
    "MRI",
    "electromagnetic fields",
    "Directive 2013/35/EU",
    "action levels",
    "RF harmonics",
    "1.5 T",
    "3 T",
    "OHS"
  ],
  "suggested_hubs": [
    {
      "slug": "occupational-exposure",
      "weight": 0.9,
      "reason": "Study assesses worker EMF exposure in MRI systems against occupational limits in EU Directive 2013/35/EU."
    }
  ]
}

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AI-extracted fields are generated from the abstract and metadata and may be incomplete or incorrect. This material is for informational purposes and is not medical advice.

Identifiers and source

DOI: 10.1016/j.ejmp.2015.03.006
PubMed: 25843889

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