title: Novel inductive decoupling technique for flexible transceiver arrays of monolithic transmission line resonators.
abstract: OBJECTIVE
  This article presents a novel inductive decoupling technique for form-fitting coil arrays of monolithic transmission line resonators, which target biomedical applications requiring high signal-to-noise ratio over a large field of view to image anatomical structures varying in size and shape from patient to patient.
  
  
  METHODS
  Individual transmission line resonator elements are mutually decoupled using magnetic flux sharing by overlapping annexes. This decoupling technique was evaluated by electromagnetic simulations and bench measurements for two- and four-element arrays, comparing single- and double-gap transmission line resonator designs, combined either with a basic capacitive matching scheme or inductive pickup loop matching. The best performing array was used in 7T MRI experiments demonstrating its form-fitting ability and parallel imaging potential.
  
  
  RESULTS
  The inductively matched double-gap transmission line resonator array provided the best decoupling efficiency in simulations and bench measurements (<-15 dB). The decoupling and parallel imaging performance proved robust against mechanical deformation of the array.
  
  
  CONCLUSIONS
  The presented decoupling technique combines the robustness of conventional overlap decoupling regarding coil loading and operating frequency with the extended field of view of nonoverlapped coils. While demonstrated on four-element arrays, it can be easily expanded to fabricate readily decoupled form-fitting 2D arrays with an arbitrary number of elements in a single etching process.
authors.affiliation: Laboratoire d'Imagerie par Résonance Magnétique Médicale et Multi-Modalités (IR4M), UMR8081 Univ Paris-Sud - CNRS, Orsay, France; Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Währinger Gürtel 18-20, 1090, Vienna, Austria; MR Centre of Excellence, Medical University of Vienna, Lazarettgasse 14, 1090, Vienna, Austria.
authors.forename: Roberta
authors.initials: R
authors.lastname: Kriegl
authors.forename: Jean-Christophe
authors.initials: JC
authors.lastname: Ginefri
authors.forename: Marie
authors.initials: M
authors.lastname: Poirier-Quinot
authors.forename: Luc
authors.initials: L
authors.lastname: Darrasse
authors.forename: Sigrun
authors.initials: S
authors.lastname: Goluch
authors.forename: Andre
authors.initials: A
authors.lastname: Kuehne
authors.forename: Ewald
authors.initials: E
authors.lastname: Moser
authors.forename: Elmar
authors.initials: E
authors.lastname: Laistler
mesh_terms: D004582:Electronics, Medical / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007089:Image Enhancement / Q000295:instrumentation*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation*; D008280:Magnetics / Q000295:instrumentation*; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014159:Transducers
keywords: coil array; mutual decoupling; pickup loop matching; surface coil; transmission line resonator; ultrahigh field