title: [Stent artifacts in 3D MR angiography: experimental studies].
abstract: OBJECTIVE
  The purpose of this phantom study was to evaluate the visualization of vascular stents by using contrast-enhanced (CE) 3D MR angiography (MRA).
  
  
  METHODS
  The measurements were performed on a Magnetom Vision operating at 1.5 T with 25 mT/m gradients by using a head coil; a 3D FISP sequence (TR/TE/FA 4.6 ms/1.8 ms/30 degrees) was used. A phantom was designed with a length of 20 cm and consisted of a plastic cylinder filled with hydrogel. Tubes were used to install 7 different stents (Strecker, Boston Scientific; Cragg, Mintec; Wall, Schneider; Memotherm, Angiomed; St-Come, Trigon-MTS; Sinus, Optimed; Palmaz, Johnson & Johnson) with different metal components. The tubes were perfused with a solution of water and Gd-DTPA. Four radiologists evaluated the image quality. The measurements of the endoluminal stent diameters were compared with the findings obtained by digital subtraction angiography. The signal intensities were measured before (inflow), within (stent) and after (outflow) the different stent types.
  
  
  RESULTS
  The endoluminal diameter of the Cragg stent and the strecker graft were easily detectable. The signal loss within the lumen of the Wall stent was approx. 10% in relation to the inflow and outflow measurements. The result was an only slightly reduced image quality. The other grafts (St-Come, Sinus, Palmaz, Memotherm) showed significant signal losses ranging from 65% to 96%. A correct diagnosis was not possible within these graft lumina.
  
  
  CONCLUSIONS
  Contrast-enhanced MR angiography can be used to evaluate vascular stents. A prerequisite is the application of particular commercially available grafts.
authors.affiliation: Abt. Röntgendiagnostik I, Klinikum der Georg-August-Universität Göttingen.
authors.forename: F
authors.initials: F
authors.lastname: Baum
authors.forename: R
authors.initials: R
authors.lastname: Vosshenrich
authors.forename: U
authors.initials: U
authors.lastname: Fischer
authors.forename: E
authors.initials: E
authors.lastname: Castillo
authors.forename: E
authors.initials: E
authors.lastname: Grabbe
mesh_terms: D015901:Angiography, Digital Subtraction; D016477:Artifacts; D003287:Contrast Media; D005069:Evaluation Studies as Topic; D019786:Gadolinium DTPA; D006801:Humans; D018810:Magnetic Resonance Angiography / Q000379:methods*; D019047:Phantoms, Imaging; D015607:Stents
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA