title: Dynamic MR imaging of a minipig's knee using a high-density multi-channel receive array and a movement device.
abstract: OBJECTIVE
  To construct an optimised, high-density receive array and a movement device to achieve dynamic imaging of the knee in orthopedic large animal models (e.g., minipigs) at 1.5 T.
  
  
  METHODS
  A 13-channel RF receive array was constructed, and the crucial choice of the array element size (based on considerations like region of interest, geometry of the minipig's knee, achievable signal-to-noise ratio, applicability of parallel imaging, etc.) was determined using the Q factors of loops with different sizes. A special movement device was constructed to guide and produce a reproducible motion of the minipig's knee during acquisition.
  
  
  RESULTS
  The constructed array was electrically characterised and the reproducibility of the cyclic motion was validated. Snapshots of dynamic in vivo images taken at a temporal resolution (308 ms) are presented. Some of the fine internal structures within the minipig's knee, like cruciate ligaments, are traced in the snapshots.
  
  
  CONCLUSIONS
  This study is a step towards making dynamic imaging which can give additional information about joint injuries when static MRI is not able to give sufficient information, a routine clinical application. There, the combination of a high-density receive array and a movement device will be highly helpful in the diagnosis and therapy monitoring of knee injuries in the future.
authors.affiliation: Research Center Magnetic Resonance Bavaria (MRB), Am Hubland, 97074, Wuerzburg, Germany. ramesh@physik.uni-wuerzburg.de
authors.forename: Sairamesh
authors.initials: S
authors.lastname: Raghuraman
authors.forename: Joachim H X
authors.initials: JH
authors.lastname: Schrauth
authors.forename: Daniel L
authors.initials: DL
authors.lastname: Weber
authors.forename: Frank
authors.initials: F
authors.lastname: Resmer
authors.forename: Meike
authors.initials: M
authors.lastname: Haddad-Weber
authors.forename: Felix A
authors.initials: FA
authors.lastname: Breuer
authors.forename: Ulrich
authors.initials: U
authors.lastname: Nöth
authors.forename: Peter M
authors.initials: PM
authors.lastname: Jakob
authors.forename: Titus
authors.initials: T
authors.lastname: Lanz
authors.forename: Daniel
authors.initials: D
authors.lastname: Haddad
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D004867:Equipment Design; D007596:Joints / Q000033:anatomy & histology* / Q000502:physiology*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation* / Q000706:statistics & numerical data; D023421:Models, Animal; D019047:Phantoms, Imaging; D013552:Swine; D013556:Swine, Miniature / Q000033:anatomy & histology / Q000502:physiology; D014741:Video Recording