title: [In vitro investigation of biological and technical prosthetic heart valves using MRI: evaluation of possible deflection and heating of the implants].
abstract: OBJECTIVE
  In vitro evaluation of possible deflection and heating of present-day prosthetic heart valves during MR imaging at 1.5 T.
  
  
  METHODS
  17 prosthetic heart valves, 12 technical and 5 biological, were investigated using a 1.5 Tesla Siemens Vision system. Deflection was measured at the edge of a 1.5 Tesla superconducting magnet. Each valve was then submerged in a vial of a 1/1 electrolyte solution and temperature was measured before and after imaging with a turbo-spin-echo sequence (TR 5200 ms, TE 138 ms, Flip angle 180 degrees, acquisition time 10.5 minutes, length of echo train 29). MR imaging was performed with phase encoding parallel and perpendicular to the plane of the valves.
  
  
  RESULTS
  None of the investigated prosthetic heart valves were deflected. The maximal observed temperature rise was 0.5 degree C. During MR investigation of the prostheses, artifacts caused by metallic parts were less evident using a spin-echo sequence than a gradient-echo sequence.
  
  
  CONCLUSIONS
  Patients with the tested present-day prosthetic heart valves can be safely imaged by MRI.
authors.affiliation: Klinik und Poliklinik für Radiologie, Johannes Gutenberg Universität Mainz. kalden@radiologie.klinik.uni-mainz.de
authors.forename: P
authors.initials: P
authors.lastname: Kalden
authors.forename: D
authors.initials: D
authors.lastname: Prüfer
authors.forename: W
authors.initials: W
authors.lastname: Schreiber
authors.forename: K F
authors.initials: KF
authors.lastname: Kreitner
authors.forename: H
authors.initials: H
authors.lastname: Oelert
authors.forename: M
authors.initials: M
authors.lastname: Thelen
mesh_terms: D001705:Bioprosthesis; D006350:Heart Valve Prosthesis; D006801:Humans; D008279:Magnetic Resonance Imaging; D011474:Prosthesis Design; D011475:Prosthesis Failure