title: In vivo demonstration of magnetic guidewire steerability in a MRI system with additional gradient coils.
abstract: OBJECTIVE
  To assess the ability to control the steering of a modified guidewire actuated by the magnetic force of a magnetic resonance imaging system with additional gradient coils for selective arterial catheterization in rabbits.
  
  
  METHODS
  Selective catheterizations of the right renal artery, left renal artery, superior mesenteric artery, and iliac artery were performed on two rabbits. A 3D magnetic force was applied onto a magnetic bead placed at the tip of a guidewire. The ability of the guidewire to advance in the aorta without entering the side branches when the magnetic force was not applied was also evaluated. Steering of the guidewire was combined with a dedicated tracking system and its position was registered on the 3D model of a magnetic resonance angiography (MRA).
  
  
  RESULTS
  The magnetic catheterization of the renal arteries was successful and showed reproducibility. Superior mesenteric artery and iliac artery showed that the catheterization was feasible. These two arteries were difficult to visualize on MRA, making catheterization and setting the direction of the force more difficult. There was no inadvertent catheterization of side vessels when the guidewire was advanced with magnetic steering despite the hook shape at the tip of the guidewire caused by the alignment of the bead anisotropy with the permanent magnetic field.
  
  
  CONCLUSIONS
  This first evaluation of selective catheterization of aortic branches with a magnetic guidewire provided a successful steering in the less angled side branches and this modified guidewire was advanced in the aorta without inadvertent selective catheterization when manipulated without magnetic actuation.
authors: NanoRobotics Laboratory, Département de génie informatique et génie logiciel, École Polytechnique de Montréal, Montréal, Québec H3T 1J4, Canada.
authors: Viviane
authors: V
authors: Lalande
authors: Département de génie mécanique, École Polytechnique de Montréal, Montréal, Québec H3T 1J4, Canada.
authors: Frederick P
authors: FP
authors: Gosselin
authors: NanoRobotics Laboratory, Département de génie informatique et génie logiciel, École Polytechnique de Montréal, Montréal, Québec H3T 1J4, Canada.
authors: Manuel
authors: M
authors: Vonthron
authors: NanoRobotics Laboratory, Département de génie informatique et génie logiciel, École Polytechnique de Montréal, Montréal, Québec H3T 1J4, Canada.
authors: Benjamin
authors: B
authors: Conan
authors: NanoRobotics Laboratory, Département de génie informatique et génie logiciel, École Polytechnique de Montréal, Montréal, Québec H3T 1J4, Canada.
authors: Charles
authors: C
authors: Tremblay
authors: Département de radiologie, CHUM-Hôpital Notre-Dame, Montréal, Québec H2L 4M1, Canada.
authors: Gilles
authors: G
authors: Beaudoin
authors: Département de radiologie, CHUM-Hôpital Notre-Dame, Montréal, Québec H2L 4M1, Canada.
authors: Gilles
authors: G
authors: Soulez
authors: NanoRobotics Laboratory, Département de génie informatique et génie logiciel, École Polytechnique de Montréal, Montréal, Québec H3T 1J4, Canada.
authors: Sylvain
authors: S
authors: Martel
mesh_terms: D000818:Animals; D001158:Arteries; D002404:Catheterization; D005260:Female; D021621:Imaging, Three-Dimensional; D060328:Magnetic Phenomena; D008279:Magnetic Resonance Imaging / Q000295:instrumentation*; D011817:Rabbits