title: Influence of cardiac motion on stent lumen visualization in third generation dual-source CT employing a pulsatile heart model.
abstract: OBJECTIVE
  To detect an in-stent restenosis, an invasive coronary angiography is commonly performed. Owing to the risk associated with this procedure, a non-invasive method to detect or exclude an in-stent restenosis is desirable. The purpose of this study was to evaluate the influence of cardiac motion on stent lumen visibility in a third-generation dual-source CT scanner (SOMATOM Force; Siemens Healthcare, Forchheim, Germany), employing a pulsatile heart model (CoroSim®; Mecora, Aachen, Germany).
  
  
  METHODS
  13 coronary stents with a diameter of 3.0 mm were implanted in plastic tubes filled with a contrast medium and then fixed onto the pulsatile phantom heart model. The scans were performed while the heart model mimicked the heartbeat. Coronary stents were scanned in an orientation parallel to the scanner z-axis. The evaluation of the stents was performed by employing a medium sharp convolution kernel optimized for vascular imaging.
  
  
  RESULTS
  The mean visible stent lumen was reduced from 65.6 ± 5.7% for the stents at rest to 60.8 ± 4.4% for the stents in motion (p-value: <0.001).
  
  
  CONCLUSIONS
  While the difference in lumen visibility between stents in motion and at rest was significant, the use of this third-generation dual-source CT scanner enabled a high stent lumen visibility under the influence of cardiac motion. Whether this translates into a clinical setting has to be evaluated in further patient studies. Advances in knowledge: The employed modern CT scanner enables a high stent lumen visibility even under the influence of cardiac motion, which is important to detect or exclude an in-stent restenosis.
authors.affiliation: 1 Department of Internal Medicine I, University Hospital of Würzburg, Würzburg, Germany.
authors.forename: Nils
authors.identifier: http://orcid.org/0000-0001-9207-2260
authors.initials: N
authors.lastname: Petri
authors.affiliation: 2 Department of Diagnostic and Interventional Radiology, University Hospital of Würzburg, Würzburg, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Gassenmaier
authors.affiliation: 3 Siemens Healthcare, Forchheim, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Allmendinger
authors.affiliation: 3 Siemens Healthcare, Forchheim, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Flohr
authors.affiliation: 1 Department of Internal Medicine I, University Hospital of Würzburg, Würzburg, Germany.
authors.forename: Wolfram
authors.initials: W
authors.lastname: Voelker
authors.affiliation: 2 Department of Diagnostic and Interventional Radiology, University Hospital of Würzburg, Würzburg, Germany.
authors.forename: Thorsten A
authors.initials: TA
authors.lastname: Bley
mesh_terms: D000072226:Computed Tomography Angiography / Q000592:standards*; D023903:Coronary Restenosis / Q000000981:diagnostic imaging*; D003971:Diastole; D006321:Heart; D006801:Humans; D008953:Models, Anatomic; D009068:Movement; D019047:Phantoms, Imaging; D011673:Pulsatile Flow; D015607:Stents; D013599:Systole; D014654:Vascular Patency