Esaote O-scan eXP, User Manual

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350004900 Rev. 07 23 / 48
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Instructions for Safe Use
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fig. 3.4 - Regions of maximum magnetic field and magnetic field gradient
The values measured in the defined regions are as follows:
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Maximum main magnetic field: B0 = 1.1027 mT
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Maximum spatial gradient of main magnetic field: 9,2398 T/m
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Maximum result: (B0) x (spatial gradient B0) = 10.1887 mT
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/m
Personnel and patient exposure to the time-varying magnetic field
A time-varying magnetic field induces an electric field E according to
Faraday's Law. The gradient coils in MR systems generate a time-varying
magnetic field, and therefore the body of the patient is exposed to an
induced electric field. This electric field can stimulate the heart, the
peripheral nervous system and the muscles, with thresholds that vary
according to frequency. The stimulation of the peripheral nervous system
(PNS) is induced by the minor gradient output values with respect to the
values required for cardiac stimulation. Therefore protection of the patient
from stimulation of the peripheral nervous system also serves to prevent
cardiac stimulation (CS).