title: MR-guided cholecystostomy: assessment of biplanar, real-time needle tracking in three pigs.
abstract: OBJECTIVE
  To demonstrate the feasibility of magnetic resonance (MR)-guided cholecystostomy using active, real-time, biplanar MR tracking in animal experiments.
  
  
  METHODS
  Experiments were performed on three fully anesthetized pigs in an interventional MR system (GE open). The gallbladder was displayed in two orthogonal planes using a heavily T2-weighted fast spin-echo sequence. These "cholangio roadmaps" were displayed on LCD monitors positioned in front of the interventionalist. A special coaxial MR-tracking needle, equipped with a small receive-only coil at its tip, was inserted percutaneously into the gallbladder under continuous, biplanar MR guidance. The MR-tracking sequence allowed sampling of the coil (needle tip) position every 120 msec. The position of the coil was projected onto the two orthogonal "cholangio roadmap" images.
  
  
  RESULTS
  Successful insertion of the needle was confirmed by aspiration of bile from the gallbladder. The process of aspiration and subsequent instillation of Gd-DTPA into the gallbladder was documented with fast gradient-recalled echo imaging.
  
  
  CONCLUSIONS
  Biplanar, active, real-time MR tracking in combination with "cholangio roadmaps" allows for cholecystostomies in an interventional MRI environment.
authors.affiliation: Department of Medical Radiology, University Hospital Zürich, Rämistrasse 100, CH-8091 Zürich, Switzerland.
authors.forename: S C
authors.initials: SC
authors.lastname: Göhde
authors.forename: T
authors.initials: T
authors.lastname: Pfammatter
authors.forename: P
authors.initials: P
authors.lastname: Steiner
authors.forename: P
authors.initials: P
authors.lastname: Erhart
authors.forename: B J
authors.initials: BJ
authors.lastname: Romanowski
authors.forename: J F
authors.initials: JF
authors.lastname: Debatin
mesh_terms: D000818:Animals; D002763:Cholecystectomy / Q000379:methods*; D005260:Female; D008279:Magnetic Resonance Imaging / Q000295:instrumentation; D013552:Swine