title: Consideration of magnetically-induced and conservative electric fields within a loaded gradient coil.
abstract: We present a method to calculate the electric (E)-fields within and surrounding a human body in a gradient coil, including E-fields induced by the changing magnetic fields and "conservative" E-fields originating with the scalar electrical potential in the coil windings. In agreement with previous numerical calculations, it is shown that magnetically-induced E-fields within the human body show no real concentration near the surface of the body, where nerve stimulation most often occurs. Both the magnetically-induced and conservative E-fields are shown to be considerably stronger just outside the human body than inside it, and under some circumstances the conservative E-fields just outside the body can be much larger than the magnetically-induced E-fields there. The order of gradient winding and the presence of conductive RF shield can greatly affect the conservative E-field distribution in these cases. Though the E-fields against the outer surface of the body are not commonly considered, understanding gradient E-fields may be important for reasons other than peripheral nerve stimulation (PNS), such as potential interaction with electrical equipment.
authors: Department of Radiology, Pennsylvania State University College of Medicine, Hershey, 17033, USA.
authors: Weihua
authors: W
authors: Mao
authors: Blaine A
authors: BA
authors: Chronik
authors: Rebecca E
authors: RE
authors: Feldman
authors: Michael B
authors: MB
authors: Smith
authors: Christopher M
authors: CM
authors: Collins