title: Carotid artery stents on CT angiography: in vitro comparison of different stent designs and sizes using 16-, 64- and 320-row CT scanners.
abstract: OBJECTIVE
  CT angiography (CTA) is an increasingly used method for evaluation of stented vessel segments. Our aim was to compare the appearance of different carotid artery stents in vitro on CTA using different CT scanners. Of particular interest was the measurement of artificial lumen narrowing (ALN) caused by the stent material within the stented vessel segment to determine whether CTA can be used to detect in-stent restenosis.
  
  
  METHODS
  CTA appearances of 16 carotid artery stents of different designs and sizes (4.0 to 11.0 mm) were investigated in vitro. CTA was performed using 16-, 64- and 320-row CT scanners. For each stent, artificial lumen narrowing (ALN) was calculated.
  
  
  RESULTS
  ALN ranged from 18.77% to 59.86%. ALN in different stents differed significantly. In most stents, ALN decreased with increasing stent diameter. In all but one stents, ALN using sharp image kernels was significantly lower than ALN using medium image kernels. Considering all stents, ALN did not significantly differ using different CT scanners or imaging protocols.
  
  
  CONCLUSIONS
  CTA evaluation of vessel patency after stent placement is possible, but is considerably impaired by ALN. Investigators should be informed about the method of choice for every stent and stent manufacturers should be aware of potential artifacts caused by their stents during noninvasive diagnostic methods such as CTA.
authors.affiliation: Division of Neuroradiology, Department of Neurosurgery, University of Freiburg, Medical Center, Breisacher Street 64, 79106 Freiburg, Germany; Division of Neuroradiology, Department of Neurology, University of Heidelberg, Medical Center, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany. Electronic address: michael_lettau@gmx.de.
authors.forename: Michael
authors.initials: M
authors.lastname: Lettau
authors.affiliation: Department of Radiology, University of Freiburg Medical Center, Breisacher Street 64, 79106 Freiburg, Germany.
authors.forename: Elmar
authors.initials: E
authors.lastname: Kotter
authors.affiliation: Division of Neuroradiology, Department of Neurology, University of Heidelberg, Medical Center, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Bendszus
authors.affiliation: Division of Neuroradiology, Department of Neurology, University of Heidelberg, Medical Center, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Hähnel
mesh_terms: D000792:Angiography / Q000295:instrumentation* / Q000379:methods; D001807:Blood Vessel Prosthesis / Q000009:adverse effects*; D002339:Carotid Arteries / Q000000981:diagnostic imaging* / Q000601:surgery; D002340:Carotid Artery Diseases / Q000000981:diagnostic imaging* / Q000209:etiology; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006083:Graft Occlusion, Vascular / Q000000981:diagnostic imaging* / Q000209:etiology; D066298:In Vitro Techniques; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D015607:Stents / Q000009:adverse effects*; D014057:Tomography, X-Ray Computed / Q000295:instrumentation* / Q000379:methods
keywords: ALN; CTA; Carotid artery stents; Different CT scanners; In vitro