title: Polarization of the RF field in a human head at high field: a study with a quadrature surface coil at 7.0 T.
abstract: The RF field intensity distribution in the human brain becomes inhomogeneous due to wave behavior at high field. This is further complicated by the spatial distribution of RF field polarization that must be considered to predict image intensity distribution. An additional layer of complexity is involved when a quadrature coil is used for transmission and reception. To study such complicated RF field behavior, a computer modeling method was employed to investigate the RF field of a quadrature surface coil at 300 MHz. Theoretical and experimental results for a phantom and the human head at 7.0 T are presented. The results are theoretically important and practically useful for high-field quadrature coil design and application.
authors.affiliation: Center for NMR Research, Department of Radiology, Pennsylvania State University College of Medicine, Hershey 17033, USA.
authors.forename: Jinghua
authors.initials: J
authors.lastname: Wang
authors.forename: Qing X
authors.initials: QX
authors.lastname: Yang
authors.forename: Xiaoliang
authors.initials: X
authors.lastname: Zhang
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Collins
authors.forename: Michael B
authors.initials: MB
authors.lastname: Smith
authors.forename: Xiao-Hong
authors.initials: XH
authors.lastname: Zhu
authors.forename: Gregor
authors.initials: G
authors.lastname: Adriany
authors.forename: Kamil
authors.initials: K
authors.lastname: Ugurbil
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
mesh_terms: D001921:Brain / Q000033:anatomy & histology*; D003198:Computer Simulation; D004574:Electromagnetic Fields; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D019047:Phantoms, Imaging; D012815:Signal Processing, Computer-Assisted