title: Tracking planar orientations of active MRI needles.
abstract: OBJECTIVE
  To determine and track the planar orientation of active interventional devices without using localizing RF microcoils.
  
  
  METHODS
  An image-based tracking method that determines a device's orientation using projection images was developed. An automated and a manual detection scheme were implemented. The method was demonstrated in an in vivo mesocaval puncture procedure in swine, which required accurate orientation of an active transvascular needle catheter.
  
  
  RESULTS
  The plane of the catheter was determined using two projection images. The scan plane was adjusted automatically to follow the catheter plane, and its orientation with respect to a previously acquired target plane was displayed. The algorithm facilitated navigation for a fast and accurate puncture.
  
  
  CONCLUSIONS
  Using image-based techniques, with no mechanical design changes, the orientation of an active intravascular probe could be tracked.
authors.affiliation: Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, Maryland, USA.
authors.forename: Shashank
authors.initials: S
authors.lastname: Sathyanarayana
authors.forename: Pelin
authors.initials: P
authors.lastname: Aksit
authors.forename: Aravind
authors.initials: A
authors.lastname: Arepally
authors.forename: Parag V
authors.initials: PV
authors.lastname: Karmarkar
authors.forename: Meiyappan
authors.initials: M
authors.lastname: Solaiyappan
authors.forename: Ergin
authors.initials: E
authors.lastname: Atalar
mesh_terms: D000465:Algorithms; D001331:Automation; D002404:Catheterization; D004867:Equipment Design; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D053783:Magnetic Resonance Imaging, Interventional / Q000379:methods*; D009339:Needles; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D014867:Water / Q000737:chemistry
chemical_list: D014867:Water