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| | '''de Vocht et al 2003''' PMID 14523950 | | '''de Vocht et al 2003''' PMID 14523950 |
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| + | Subjects performed neurobehavioral tests while inside the bore of a 1.5T MRI machine; for controls, subjects were tested in the same MRI machine but with the magnet OFF. Deficits in hand eye coordination and visual contrast were found. No effect was found of movement or gradient fields. |
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| − | '''de Vocht et al 2006''' PMID 16374876
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| − | Survey of complaints among MRI manufacturing workers at Philips Medical Systems. Nice features: videotaped workers moving around 1.0 T and 1.5 T magnets, so got estimate of movement speed and magnetic field exposure; used X-ray assembly workers as a control group.
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| − | "Dizziness, concentration problems, metallic taste, and suggestions of head ringing were significantly more reported by exposed workers, with the latter two only being reported near 1.5-T MRI systems....Our results show that employees from an MRI manufacturing department who moved more rapidly in the RF cage and consequently generated a stronger dynamic field, indeed reported more complaints than individuals who moved at a slower pace through the SMFs. Furthermore, moving speed and intensity was found to be to a large extent a personal characteristic, with a large between-subject and a small within-subject variance."
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| − | '''de Vocht et al 2006''' PMID 16463303
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| − | Subjects seated right outside a 1.5 T and 3.0 T MRI machine to assess effects of stray field on neurobehavioral tests. Found deficits in hand-eye coordination, visual tracking, and processing of auditory and visual information.
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| − | "This study confirms that eye– hand coordination and the visual domain are affected by exposure to SMFs. In addition, our results suggest that processing of visual and auditive information is also affected, and that an exposure–response relation exists for visual and audi-tive working memory, eye– hand coordination speed, and visual-tracking tasks. However, since the stray fields to which the volunteers were exposed were very inhomogeneous, it was difficult to assess the actual exposure in a given time interval. Therefore, it remains unclear whether the speed of motion in combination with the gradient or the SMF strength is the more imporant factor in causing the neurobehavioral effects."
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| − | '''de Vochet et al 2007''' PMID 17290435
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| − | Subjects seated right outside a 7T MRI machine to assess effects of stray field on neurobehavioral tests; highest exposure was 1.6 - 2.0 T (but a very high gradient). Deficits in visual tracking were found after head movements in the stray field, which might be secondary to vestibular effects (although no vertigo is reported in this paper).
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| − | "As shown, only visual tracking performance … differed significantly (P <.01) between different levels of static magnetic field exposure, and the magnitude of the effect also depended on the magnitude of the exposure (P <.01). Performance of the Pursuit Aiming II-test (P =.09) and the time to complete the line bisection-test (P =.06) showed a trend towards dependence on the magnitude of exposure, with borderline statistical significance. There was also a trend for the average deviance in the line bisection-test to improve with increased exposure (P =.08)....Since this and previous studies suggest that cognitive effects occur particularly in the visual sensory domain, a possible mechanism might be that the widely recognized "vertigo’’ effect of moving in a magnetic field, might interfere with the vestibulo-ocular reflex." | + | "After adjustment for the learning effect, speed and precision (Pursuit Aiming II) and near visual contrast sensitivity (Vistech 6000TM; 1.5 and 3.0 cycles per degree) were negatively influenced (– 4% (P |
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