title: Interactive MR imaging and tracking of catheters with multiple tuned fiducial markers.
abstract: OBJECTIVE
  The lack of magnetic resonance (MR) safe catheters and guide wires remains an important obstacle to widespread clinical use of MR-guided endovascular procedures. The authors looked at the feasibility of using multiple tuned fiducial markers (TFM) and novel imaging sequences to track catheters reliably under MR and to evaluate the safety of such markers in terms of heating.
  
  
  METHODS
  The visualization and tracking of a catheter with six quadrature tuned fiducial coils was carried out in a special designed in-vitro setup within a 1.5-T MR imager simulating an MR-guided endovascular intervention. The fiducial markers were also tested for heating.
  
  
  RESULTS
  The excellent signal contrast between the fiducial and the background when using novel interleaved real time and interactive sequences allowed for rapid and reliable identification of the fiducial markers and therefore the catheter. No significant heating of the marker was noted.
  
  
  CONCLUSIONS
  The authors have shown that catheters with multiple tuned fiducial markers are superior to passive catheter designs in terms of visualization and do not carry the risk of heating that is commonly associated with active catheters.
authors.affiliation: Division of Imaging Sciences, King's College London School of Medicine, Guy's Campus, London SE1 9RT, UK.
authors.forename: Sanjeet
authors.initials: S
authors.lastname: Hegde
authors.forename: Marc E
authors.initials: ME
authors.lastname: Miquel
authors.forename: Redha
authors.initials: R
authors.lastname: Boubertakh
authors.forename: David
authors.initials: D
authors.lastname: Gilderdale
authors.forename: Vivek
authors.initials: V
authors.lastname: Muthurangu
authors.forename: Stephen F
authors.initials: SF
authors.lastname: Keevil
authors.forename: Ian
authors.initials: I
authors.lastname: Young
authors.forename: Derek L G
authors.initials: DL
authors.lastname: Hill
authors.forename: Reza S
authors.initials: RS
authors.lastname: Razavi
mesh_terms: D006328:Cardiac Catheterization / Q000295:instrumentation / Q000379:methods*; D005240:Feasibility Studies; D006358:Hot Temperature; D066298:In Vitro Techniques; D008279:Magnetic Resonance Imaging; D019047:Phantoms, Imaging