title: Asymmetric quadrature split birdcage coil for hyperpolarized 3He lung MRI at 1.5T.
abstract: An asymmetric quadrature birdcage body coil for hyperpolarized (HP) (3)He lung imaging at 1.5T is presented. The coil is designed to rest on top of the patient support and be used as a temporary insert in a clinical system. A two-part construction facilitates patient access and the asymmetric design makes maximal use of available bore space to ensure comfort. Highly homogeneous, circularly polarized RF magnetic fields are produced at 48.5 MHz using a conformal mapping method for the geometrical design, combined with an algebraic method to calculate the individual capacitance values on the birdcage coil's ladder network. Efficiency and isolation from the system's proton body coil are ensured by an integrated RF screen. The design methodology is readily applicable to other field strengths or nuclei. Improvements over existing (3)He coils were found in terms of sensitivity and transmit field homogeneity, an important feature in HP MRI.
authors.affiliation: Institute for Biomedical Engineering, University of Zurich and ETH Zurich, Zurich, Switzerland.
authors.forename: Nicola
authors.initials: N
authors.lastname: De Zanche
authors.forename: Navjeet
authors.initials: N
authors.lastname: Chhina
authors.forename: Kevin
authors.initials: K
authors.lastname: Teh
authors.forename: Chris
authors.initials: C
authors.lastname: Randell
authors.forename: Klaas P
authors.initials: KP
authors.lastname: Pruessmann
authors.forename: Jim M
authors.initials: JM
authors.lastname: Wild
mesh_terms: D017076:Computer-Aided Design; D003287:Contrast Media; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006371:Helium; D006801:Humans; D007089:Image Enhancement / Q000295:instrumentation* / Q000379:methods; D007554:Isotopes; D008168:Lung / Q000033:anatomy & histology*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation*; D008280:Magnetics / Q000295:instrumentation*; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014159:Transducers
chemical_list: D003287:Contrast Media; D007554:Isotopes; D006371:Helium