title: Multislice spiral computed tomography for the detection of coronary stent restenosis and patency.
abstract: BACKGROUND
  Multislice spiral computed tomography (MSCT) has evolved as a new promising method for non-invasive visualization of the coronary arteries and detection of native coronary artery stenosis. We determined the value of MSCT to non-invasively detect significant in-stent restenosis after coronary artery stenting.
  
  
  METHODS
  Twenty patients (age 56.3+/-8.6 years) were investigated by MSCT (4x1 mm cross-sections, 500 ms tube rotation, table feed 1.5 mm/rotation, intravenous contrast agent, retrospectively ECG-gated image reconstruction) at a mean interval of 9.6+/-4.2 months after coronary stent implantation. Results were compared with conventional quantitative coronary angiography (QCA). A total number of 32 stents were studied, four different stent types were evaluated.
  
  
  RESULTS
  QCA showed in-stent restenosis >50% diameter stenosis in five (16%) stents. Using MSCT it was impossible in all stents, irrespective of stent type or diameter, to directly visualize the stent lumen due to partial volume effects and beam hardening. MSCT allowed the visualization of the coronary vessel proximal and distal to the stent. This allowed confirmation of stent patency in 18/18 cases and correct identification of total stent occlusion in two patients.
  
  
  CONCLUSIONS
  MSCT allows no direct visualization of coronary in-stent restenosis, but it correctly differentiates between stent patency and stent occlusion. The reasons are mainly partial volume effects and beam hardening, which are induced by the stent material.
authors.affiliation: Medical Clinic I, University Hospital, University of Technology, Aachen, Germany. rhoffmann@ukaachen.de <rhoffmann@ukaachen.de>
authors.forename: Stefan
authors.initials: S
authors.lastname: Krüger
authors.forename: Andreas H
authors.initials: AH
authors.lastname: Mahnken
authors.forename: Anil M
authors.initials: AM
authors.lastname: Sinha
authors.forename: Anja
authors.initials: A
authors.lastname: Borghans
authors.forename: Katrin
authors.initials: K
authors.lastname: Dedden
authors.forename: Rainer
authors.initials: R
authors.lastname: Hoffmann
authors.forename: Peter
authors.initials: P
authors.lastname: Hanrath
mesh_terms: D017023:Coronary Angiography / Q000379:methods*; D023903:Coronary Restenosis / Q000000981:diagnostic imaging* / Q000209:etiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009204:Myocardial Revascularization / Q000009:adverse effects*; D015607:Stents / Q000009:adverse effects*; D036542:Tomography, Spiral Computed / Q000295:instrumentation*; D014654:Vascular Patency