title: 64- Versus 16-slice CT angiography for coronary artery stent assessment: in vitro experience.
abstract: OBJECTIVE
  We sought to assess the visualization of different coronary artery stents and the delineation of in-stent stenoses using 64- and 16-slice multidector computed tomography (MDCT).
  
  
  METHODS
  A total of 15 different coronary stents with a simulated in-stent stenosis were placed in a vascular phantom and scanned with a 16-slice and a 64-slice MDCT at orientations of 0 degree, 45 degrees, and 90 degrees relative to the scanner's z-axis. Visible lumen diameter and attenuation in the stented and the unstented segment of the phantom were measured. Three readers assessed stenosis delineation and visualization of the residual lumen using a 5-point scale.
  
  
  RESULTS
  Artificial lumen narrowing (ALN) was significantly reduced with 64-slice CT compared with 16-slice CT. At an angle of 0 degree, 45 degrees, and 90 degrees relative to the scanner's z-axis, the ALN for 16-slice CT was 42.2%, 39.8%, and 44.0% using a slice-thickness of 1.0 mm and 40.9%, 40.4%, and 41.6% using a slice thickness of 0.75 mm, respectively. With 64-slice CT, the ALN was 39.1%, 37.3%, and 36.0% at the respective angles. The differences between attenuation values in the stented and unstented segment of the tube were significantly lower for 64-slice CT. Mean visibility scores were significantly higher for 64-slice CT.
  
  
  CONCLUSIONS
  Use of the 64-slice CT results in superior visualization of the stent lumen and in-stent stenosis compared with 16-slice CT, especially when the stent is orientated parallel to the x-ray beam.
authors.affiliation: Department of Clinical Radiology, University of Muenster, Germany. seifarth@uni-muenster.de
authors.forename: Harald
authors.initials: H
authors.lastname: Seifarth
authors.forename: Murat
authors.initials: M
authors.lastname: Ozgün
authors.forename: Rainer
authors.initials: R
authors.lastname: Raupach
authors.forename: Thomas
authors.initials: T
authors.lastname: Flohr
authors.forename: Walter
authors.initials: W
authors.lastname: Heindel
authors.forename: Roman
authors.initials: R
authors.lastname: Fischbach
authors.forename: David
authors.initials: D
authors.lastname: Maintz
mesh_terms: D017023:Coronary Angiography / Q000379:methods*; D023921:Coronary Stenosis / Q000000981:diagnostic imaging* / Q000601:surgery; D006083:Graft Occlusion, Vascular / Q000000981:diagnostic imaging*; D007091:Image Processing, Computer-Assisted; D066298:In Vitro Techniques; D019047:Phantoms, Imaging; D015641:Radiography, Interventional; D018709:Statistics, Nonparametric; D015607:Stents; D014057:Tomography, X-Ray Computed / Q000379:methods*