title: Improved coronary in-stent visualization using a combined high-resolution kernel and a hybrid iterative reconstruction technique at 256-slice cardiac CT-Pilot study.
abstract: OBJECTIVE
  To investigate the diagnostic performance of 256-slice cardiac CT for the evaluation of the in-stent lumen by using a hybrid iterative reconstruction (HIR) algorithm combined with a high-resolution kernel.
  
  
  METHODS
  This study included 28 patients with 28 stents who underwent cardiac CT. Three different reconstruction images were obtained with: (1) a standard filtered back projection (FBP) algorithm with a standard cardiac kernel (CB), (2) an FBP algorithm with a high-resolution cardiac kernel (CD), and (3) an HIR algorithm with the CD kernel. We measured image noise and kurtosis and used receiver operating characteristics analysis to evaluate observer performance in the detection of in-stent stenosis.
  
  
  RESULTS
  Image noise with FBP plus the CD kernel (80.2 ± 15.5 HU) was significantly higher than with FBP plus the CB kernel (28.8 ± 4.6 HU) and HIR plus the CD kernel (36.1 ± 6.4 HU). There was no significant difference in the image noise between FBP plus the CB kernel and HIR plus the CD kernel. Kurtosis was significantly better with the CD- than the CB kernel. The kurtosis values obtained with the CD kernel were not significantly different between the FBP- and HIR reconstruction algorithms. The areas under the receiver operating characteristics curves with HIR plus the CD kernel were significantly higher than with FBP plus the CB- or the CD kernel. The difference between FBP plus the CB- or the CD kernel was not significant. The average sensitivity, specificity, and positive and negative predictive value for the detection of in-stent stenosis were 83.3, 50.0, 33.3, and 91.6% for FBP plus the CB kernel, 100, 29.6, 40.0, and 100% for FBP plus the CD kernel, and 100, 54.5, 40.0, and 100% for HIR plus the CD kernel.
  
  
  CONCLUSIONS
  The HIR algorithm combined with the high-resolution kernel significantly improved diagnostic performance in the detection of in-stent stenosis.
authors.affiliation: Department of Diagnostic Radiology, Faculty of Life Sciences, Kumamoto University, 1-1-1 Honjyo, Kumamoto 860-8556, Japan. seisei0430@nifty.com
authors.forename: Seitaro
authors.initials: S
authors.lastname: Oda
authors.forename: Daisuke
authors.initials: D
authors.lastname: Utsunomiya
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Funama
authors.forename: Hiroko
authors.initials: H
authors.lastname: Takaoka
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Katahira
authors.forename: Keiichi
authors.initials: K
authors.lastname: Honda
authors.forename: Katsuo
authors.initials: K
authors.lastname: Noda
authors.forename: Shuichi
authors.initials: S
authors.lastname: Oshima
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Yamashita
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D017023:Coronary Angiography / Q000379:methods*; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000601:surgery*; D023903:Coronary Restenosis / Q000000981:diagnostic imaging* / Q000209:etiology; D005260:Female; D006083:Graft Occlusion, Vascular / Q000000981:diagnostic imaging* / Q000209:etiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011856:Radiographic Image Enhancement / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D015607:Stents / Q000009:adverse effects*; D014057:Tomography, X-Ray Computed / Q000379:methods*; D016896:Treatment Outcome