Effects of magnetic stray fields from a 7 Tesla MRI scanner on neurocognition: a double-blind randomised crossover study

Nierop, Lotte E. van; Slottje, Pauline; Zandvoort, M.J.E. van; Vocht, Frank de; Kromhout, Hans

doi:10.1136/oemed-2011-100468

Cited by 53 publications

(40 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…No significant effects on cognitive function were found at any field strength or condition [35 • ]. In contrast, studies by the group of De Vocht showed some small but significant effects on attention/concentration and visuospatial orientation when the subject was positioned in the stray field of a 7 T scanner both when stationary and also after moving their head [36,37]. Bearing in mind the recent studies, discussed previously, on nystagmus, it would be interesting to investigate whether this could explain the observed cognitive effects in the visuospatial and attention/concentration domain, and to replicate the possible relation between nystagmus and these cognitive effects in a magnetic field free environment during vestibular activation [38].…”

Section: Biological Effects Of the Main Magnetic Field Strengthmentioning

confidence: 83%

Safety of Ultra-High Field MRI: What are the Specific Risks?

Osch

Webb

2014

Curr Radiol Rep

View full text Add to dashboard Cite

There are currently more than 50 ultra-high field (7 T and above) MRI systems installed around the world. The vast majority of these perform studies on humans, whether healthy volunteers, volunteers for clinical research, or actual patients. The increased magnetic field strength potentially raises new safety concerns in the areas of the effects of the static magnetic field itself, increased power deposition due to the higher operating frequency, and acoustic noise. There are currently very different operational modes in different institutions, with policies effectively set by local ethics committees. This article summarizes the current legal and practical status regarding safety of ultra-high field MRI.

show abstract

Section: Biological Effects Of the Main Magnetic Field Strengthmentioning

confidence: 83%

Safety of Ultra-High Field MRI: What are the Specific Risks?

Osch

Webb

2014

Curr Radiol Rep

View full text Add to dashboard Cite

show abstract

“…Similarly, for patients, unpleasant effects (dizziness and vertigo, for example, but also tachycardia and sweating), some of which are related to the static field, are reported more often during imaging using 7 T systems than with 1.5 T systems [9]. Some of these reported effects may be related to adverse effects on visual perception, spatial orientation, visuomotor performance, working memory, and attention, measured in controlled trials [10][11][12][13]. Experimental studies similarly show that exposure to the static magnetic field has a direct negative, but temporary, effect on the vestibular system [14][15][16][17][18].…”

Section: Introductionmentioning

confidence: 99%

Transient health symptoms of MRI staff working with 1.5 and 3.0 Tesla scanners in the UK

et al. 2015

Self Cite

View full text Add to dashboard Cite

Objectives Recent studies have consistently shown that amongst staff working with MRI, transient symptoms directly attributable to the MRI system including dizziness, nausea, tinnitus, and concentration problems are reported. This study assessed symptom prevalence and incidence in radiographers and other staff working with MRI in healthcare in the UK. Methods One hundred and four volunteer staff from eight sites completed a questionnaire and kept a diary to obtain information on subjective symptoms and work practices, and wore a magnetic field dosimeter during one to three randomly selected working days. Incidence of MRI-related symptoms was obtained for all shifts and prevalence of MRI-related and reference symptoms was associated to explanatory factors using ordinal regression. Results Incident symptoms related to working with MRI were reported in 4 % of shifts. Prevalence of MRI-related, but not reference symptoms were associated with number of hours per week working with MRI, shift length, and stress, but not with magnetic field strength (1.5 and 3 T) or measured magnetic field exposure. Conclusions Reporting of prevalent symptoms was associated with longer duration of working in MRI departments, but not with measured field strength of exposure. Other factors related to organisation and stress seem to contribute to increased reporting of MRI-related symptoms. Key Points • Routine work with MRI is associated with increased reporting of transient symptoms • No link to the strength of the magnetic field was demonstrated.• Organisational factors and stress additionally contribute to reporting of MRI-related symptoms

show abstract

“…Current literature suggests that these symptoms have an acute and transient nature,10 16–18 and many of these arise when people move through the spatial gradients in the static magnetic stray field outside the MRI scanner, resulting in exposure to low-frequency TvMFs 14 17 18. In only a few studies were symptoms assessed in a (semi-)objective way, either by blinding subjects to the exposure condition, or by making inquiries about symptoms during the work day in general as opposed to specifically relating it to MRI or SMF exposure 8 15 17 19. Furthermore, in only a few studies was symptom occurrence related to different exposure conditions using statistical tests 8 9 14 15 20.…”

Section: Introductionmentioning

confidence: 99%

Occupational exposure of healthcare and research staff to static magnetic stray fields from 1.5–7 Tesla MRI scanners is associated with reporting of transient symptoms

et al. 2014

Self Cite

View full text Add to dashboard Cite

ObjectivesLimited data is available about incidence of acute transient symptoms associated with occupational exposure to static magnetic stray fields from MRI scanners. We aimed to assess the incidence of these symptoms among healthcare and research staff working with MRI scanners, and their association with static magnetic field exposure.MethodsWe performed an observational study among 361 employees of 14 clinical and research MRI facilities in The Netherlands. Each participant completed a diary during one or more work shifts inside and/or outside the MRI facility, reporting work activities and symptoms (from a list of potentially MRI-related symptoms, complemented with unrelated symptoms) experienced during a working day. We analysed 633 diaries. Exposure categories were defined by strength and type of MRI scanner, using non-MRI shifts as the reference category for statistical analysis. Non-MRI shifts originated from MRI staff who also participated on MRI days, as well as CT radiographers who never worked with MRI.ResultsVarying per exposure category, symptoms were reported during 16–39% of the MRI work shifts. We observed a positive association between scanner strength and reported symptoms among healthcare and research staff working with closed-bore MRI scanners of 1.5 Tesla (T) and higher (1.5 T OR=1.88; 3.0 T OR=2.14; 7.0 T OR=4.17). This finding was mainly driven by reporting of vertigo and metallic taste.ConclusionsThe results suggest an exposure-response association between exposure to strong static magnetic fields (and associated motion-induced time-varying magnetic fields) and reporting of transient symptoms on the same day of exposure.Trial registration number11-032/C

show abstract

Effects of magnetic stray fields from a 7 Tesla MRI scanner on neurocognition: a double-blind randomised crossover study

Cited by 53 publications

References 30 publications

Safety of Ultra-High Field MRI: What are the Specific Risks?

Safety of Ultra-High Field MRI: What are the Specific Risks?

Transient health symptoms of MRI staff working with 1.5 and 3.0 Tesla scanners in the UK

Occupational exposure of healthcare and research staff to static magnetic stray fields from 1.5–7 Tesla MRI scanners is associated with reporting of transient symptoms

Contact Info

Product

Resources

About