title: Plain and covered stent-grafts: in vitro evaluation of characteristics at three-dimensional MR angiography.
abstract: OBJECTIVE
  To evaluate the characteristics of various plain and covered stents as regards demonstration of the contained lumen with simulated contrast material-enhanced fast three-dimensional (3D) magnetic resonance (MR) angiography.
  
  
  METHODS
  Six stents (Easy Wallstent, Cragg, Palmaz, Cragg EndoPro System 1, Corvita, Passager) were implanted in plastic tubes and integrated into a closed-tubing circuit driven by a pulsatile roller flow pump. The circulating water was spiked with gadopentetate dimeglumine. Three-dimensional MR angiograms were obtained with an echo time of 1.4 or 2.1 msec and with partial (0.5 signal acquired) or full (one signal acquired) k-space sampling. The size of the stent-associated artifact was determined relative to the tube diameter.
  
  
  RESULTS
  The Easy Wallstent and Palmaz stent caused complete obliteration of the stent lumen with all sequences. The Cragg, Cragg EndoPro System 1, and Passager stents allowed good visualization of the stent lumen. The Corvita stent demonstrated major artifacts. The magnitude of the stent-associated artifact was related to the echo time (P < .01) but not to the type of k-space sampling (P = .35).
  
  
  CONCLUSIONS
  The luminal patency of selected plain and covered stents can be assessed with contrast-enhanced 3D MR angiography.
authors.affiliation: Institute of Diagnostic Radiology, University Hospital Zurich, Switzerland.
authors.forename: P R
authors.initials: PR
authors.lastname: Hilfiker
authors.forename: H H
authors.initials: HH
authors.lastname: Quick
authors.forename: J F
authors.initials: JF
authors.lastname: Debatin
mesh_terms: D001808:Blood Vessels; D020099:Coated Materials, Biocompatible; D003287:Contrast Media; D019786:Gadolinium DTPA; D018810:Magnetic Resonance Angiography; D019047:Phantoms, Imaging; D015607:Stents
chemical_list: D020099:Coated Materials, Biocompatible; D003287:Contrast Media; D019786:Gadolinium DTPA