The combined field integral equation (CFIE) method is used to calculate the RF magnetic B1 field produced by a transmission-line resonator element for high-field magnetic resonance systems. The method calculates the surface currents on a homogeneous phantom with triangular patches with the RaoWiltonGlisson (RWG) basis functions, and the tetrahedra with the SchaubertWiltonGlisson (SWG) basis functions are used to calculate the resonator element field. The transmission-line resonator element is excited at its resonant frequency and the equivalent surface current distribution over the phantom are obtained, and then the internal fields in the phantom are calculated for the 9.4-T MRI system. This integral equation method provides much faster B1 field results than the corresponding inite-difference time domain (FDTD) approach. A field localization method by adjusting phase excitations is also discussed.
Bibliographical noteFunding Information:
Manuscript received November 16, 2010; revised February 03, 2011; accepted April 06, 2011. Date of publication May 31, 2011; date of current version June 27, 2011. This work was supported by NIH R01-EB006835, BTRC P41-RR008079, and the Keck Foundation.
- Combined field integral equation (CFIE)
- magnetic resonance imaging (MRI)
- method of moments (MoM)
- radio frequency (RF) B field
- radio frequency coil
- transmission-line element