title: Evaluation of coronary stents and stenoses at different heart rates with dual source spiral CT (DSCT).
abstract: OBJECTIVE
  Evaluation of coronary arteries at higher heart rates and in the presence of coronary stents remains problematic. The utilization of dual source computed tomography (DSCT) might improve the visualization of the coronary arteries under these conditions by imaging at a temporal resolution of 83 milliseconds, independent of heart rate.
  
  
  METHODS
  Vessel phantoms (diameter 2-4 mm) were attached to a robotic device to simulate cardiac motion and scanned with a DSCT system. The phantoms had either inserts leading to 50% stenosis or carried stents. Images were evaluated for motion artifacts and measurements of the normal, stenotic, and in-stent lumen at different heart rates (50-120 bpm) were performed. Quantile regression analysis was performed to investigate heart rate dependence of the measurement errors.
  
  
  RESULTS
  Visualization of the stenoses and stents was possible without motion artifacts at heart rates of up to 120 bpm. Image quality was similar for the static (0 bpm) and the dynamic (50-120 bpm) scans. Errors for diameter measurements of the vessel lumen and the stenotic lumen were low (3-mm vessel: 1-2%), but considerable for in-stent diameter measurements (3-mm stent: 27-32%). A window/level setting of 1500/300 Hounsfield units was more favorable for stent evaluation. No heart rate dependence was found.
  
  
  CONCLUSIONS
  Depiction of coronary stents with DSCT is possible across a large range of simulated heart rates without motion artifacts and with image quality superior to that of previous generations of CT scanners.
authors.affiliation: Department of Radiological Sciences, David Geffen School of Medicine at UCLA, Los Angeles, California 90095, USA. Michael.Lell@idr.imed.uni-erlangen.de
authors.forename: Michael M
authors.initials: MM
authors.lastname: Lell
authors.forename: Christoph
authors.initials: C
authors.lastname: Panknin
authors.forename: Roya
authors.initials: R
authors.lastname: Saleh
authors.forename: James W
authors.initials: JW
authors.lastname: Sayre
authors.forename: Bernhard
authors.initials: B
authors.lastname: Schmidt
authors.forename: Howard
authors.initials: H
authors.lastname: Dinh
authors.forename: Stefan G
authors.initials: SG
authors.lastname: Ruehm
mesh_terms: D017023:Coronary Angiography; D023903:Coronary Restenosis / Q000175:diagnosis* / Q000517:prevention & control; D003331:Coronary Vessels / Q000473:pathology*; D006339:Heart Rate; D006801:Humans; D019047:Phantoms, Imaging; D015607:Stents; D036542:Tomography, Spiral Computed / Q000295:instrumentation*