title: Coronary in-stent restenosis: assessment with CT coronary angiography.
abstract: OBJECTIVE
  To compare accuracy and radiation exposure of a new computed tomographic (CT) scanner with improved spatial resolution (scanner A) with those of a CT scanner with standard spatial resolution (scanner B) for evaluation of coronary in-stent restenosis (ISR) by using invasive coronary angiography (ICA) and intravascular ultrasonography (US) as reference methods.
  
  
  METHODS
  Written informed consent was obtained and study protocol was approved by institutional ethics committee. A total of 180 consecutive patients (154 men [mean age ± standard deviation, 66 years±12; range, 51-79 years] and 36 women [mean age, 70 years±12; range, 55-83 years]) scheduled to undergo ICA for suspected ISR were enrolled. Ninety patients were studied with scanner A (group 1: 72 men [mean age, 65 years±11; range, 52-79], 18 women [mean age, 68 years±12; range, 55-83 years]) and 90 with scanner B (group 2: 74 men [mean age, 64 years±10; range, 51-77 years], 16 women [mean age, 68 years±11; range, 55-82 years). Examination with the two scanners was compared with ICA and intravascular US. Radiation dose exposure was estimated. To compare stent evaluability between the two groups, χ2 test was used.
  
  
  RESULTS
  Stent evaluability was higher in group 1 than in group 2 (99% vs 92%, P=.0021). A significantly lower rate of beam-hardening artifact was observed in group 1 (two cases) than group 2 (12 cases, P<.05). For stent-based analysis, sensitivity, specificity, and accuracy of multidetector CT for ISR identification were 96%, 95%, and 96% in group 1 and 90%, 91%, and 91% in group 2, respectively, without statistically significant differences. The correlation between percent ISR evaluated at multidetector CT versus intravascular US was higher in group 1 than in group 2 (r=0.89 vs r=0.58; P=.019). The correlations of diameter and area measurements at reference site and stent maximal lumen narrowing site between multidetector CT and intravascular US were higher in group 1 than in group 2. Radiation dose was low in both multidetector CT groups (1.9 mSv±0.2).
  
  
  CONCLUSIONS
  Scanner A, with improved spatial resolution, allowed reliable detection and quantification of coronary ISR with low radiation exposure.
authors.affiliation: Department of Cardiovascular Imaging, Centro Cardiologico Monzino, IRCCS, Via C. Parea 4, 20138 Milan, Italy. daniele.andreini@ccfm.it
authors.forename: Daniele
authors.initials: D
authors.lastname: Andreini
authors.forename: Gianluca
authors.initials: G
authors.lastname: Pontone
authors.forename: Saima
authors.initials: S
authors.lastname: Mushtaq
authors.forename: Antonio L
authors.initials: AL
authors.lastname: Bartorelli
authors.forename: Erika
authors.initials: E
authors.lastname: Bertella
authors.forename: Daniela
authors.initials: D
authors.lastname: Trabattoni
authors.forename: Piero
authors.initials: P
authors.lastname: Montorsi
authors.forename: Stefano
authors.initials: S
authors.lastname: Galli
authors.forename: Claudia
authors.initials: C
authors.lastname: Foti
authors.forename: Andrea
authors.initials: A
authors.lastname: Annoni
authors.forename: Francesca
authors.initials: F
authors.lastname: Bovis
authors.forename: Giovanni
authors.initials: G
authors.lastname: Ballerini
authors.forename: Piergiuseppe
authors.initials: P
authors.lastname: Agostoni
authors.forename: Cesare
authors.initials: C
authors.lastname: Fiorentini
authors.forename: Mauro
authors.initials: M
authors.lastname: Pepi
mesh_terms: D000368:Aged; D017023:Coronary Angiography / Q000379:methods*; 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; 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