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PubMed · 10318720

Physiologic effects of intense MR imaging gradient fields.

J D Bourland·J A Nyenhuis·D J Schaefer
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Abstract

The strength duration relationship for peripheral nerve stimulation by MR imaging pulsed gradient magnetic fields was measured in 84 human subjects. The data were fitted to the hyperbolic strength-duration relationship: dB/dt=b(1 + c/d), where b is rheobase, c is chronaxie, and d is duration, and dB/dt is reported as the maximal value on the axis of the bore. For sensation threshold, average (b,c) (15 T/s, 0.37 ms) for the y-gradient and (26 T/s, 0.38 ms) for the z-gradient coil. The dB/dt intensity to induce a sensation which the subject described as uncomfortable was about 50% above the sensation threshold. Experiments with dogs showed that the cardiac stimulation by pulsed magnetic gradient fields is exceedingly unlikely.

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Abdominal MusclesAdultAnimalsDogsElectric StimulationElectrocardiographyFemaleHumansMagnetic Resonance ImagingMagneticsMaleMuscle ContractionMuscle, SkeletalPainPain ThresholdRespirationSensationSensory ThresholdsThoraxVagus NerveJournal ArticleResearch Support, U.S. Gov't, P.H.S.

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J D Bourland, J A Nyenhuis, D J Schaefer. 1999. Physiologic effects of intense MR imaging gradient fields.. https://pubmed.ncbi.nlm.nih.gov/10318720/

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