Date of Award
2007
Degree Type
Thesis
Degree Name
Master of Science
Program
Medical Biophysics
Supervisor
Dr. Blaine Chronik
Second Advisor
Dr. Martin Zinke-Allmang
Abstract
In magnetic resonance imaging (MRI), peripheral nerve stimulation (PNS) resulting from electric fields induced from the rapidly changing magnetic fields of gradient coils is a concern. Nerves exposed to either electric fields or time-varying magnetic fields would be expected to display consistent threshold characteristics, motivating the direct application of electric field exposure criteria from literature to guide the development of gradient coil exposure criteria for MRI. The chronaxie times (an indicator of nerve excitability) for electric and magnetic PNS threshold curves were compared in two consecutive studies. Peripheral nerves were stimulated electrically and magnetically using surface electrodes and a figure-eight coil, respectively. The main finding of these studies is that chronaxie time is significantly different between electric and magnetic stimulation. These results suggests that special care must be taken when using electric field exposure data from literature to set gradient coil PNS safety standards in MRI.
Recommended Citation
Recoskie, Bryan James, "Comparison of Human Peripheral Nerve Stimulation Thresholds as Measured using Electric and Magnetic Stimuli: Relevance to MRI Gradient Safety" (2007). Digitized Theses. 4875.
https://ir.lib.uwo.ca/digitizedtheses/4875