title: Prediction of carotid artery in-stent restenosis by quantitative assessment of vulnerable plaque using computed tomography.
abstract: OBJECTIVE
  To assess the relationship between plaque volume evaluated by multidetector computed tomographic angiography (MDCT) and in-stent restenosis (ISR) after carotid artery stenting (CAS).
  
  
  METHODS
  From a retrospectively maintained database, data were collected for 52patients with carotid artery stenosis treated with CAS between 2007 and 2012. We defined ISR of≥50% as a peak systolic velocity≥200cm/s on echo-duplex scan. Carotid plaques were subdivided into four components according to radiodensity in Hounsfield units (HU) as follows: <0, 0-60, 60-130, and>600HU. Risk factors that influenced ISR were compared using univariate and multivariate Cox regression analyses.
  
  
  RESULTS
  During a median follow-up period of 36months, ISR of≥50% was detected in five patients (9.6%). In the univariate Cox proportional hazard regression analysis, renal insufficiency, coronary artery disease, total plaque volume, and plaque volumes with radiodensities<0 and≥600HU increased the risk for ISR (P<0.10). When the significant risk factors determined from the univariate analysis were subjected to a multivariate analysis, only the volumes of the plaque components with radiodensities<0 HU independently predicted the development of ISR (hazard ratio: 1.041; 95% confidence interval: 1.006-1.078; P=0.021).
  
  
  CONCLUSIONS
  Our data suggest that the high volume of the plaque components with radiodensities<0HU was independently associated with the increased risk of ISR after CAS. Quantitative and qualitative tissue characterizations of carotid plaques using MDCT might be a useful predictive tool of the development of ISR.
authors.affiliation: Kanazawa University, Graduate School of Medical Science, Division of Neuroscience, Department of Neurosurgery, 13-1 Takara-machi, Kanazawa, 920-8641 Ishikawa, Japan. Electronic address: misaki@med.kanazawa-u.ac.jp.
authors.forename: Kouichi
authors.initials: K
authors.lastname: Misaki
authors.affiliation: Kanazawa University, Graduate School of Medical Science, Division of Neuroscience, Department of Neurosurgery, 13-1 Takara-machi, Kanazawa, 920-8641 Ishikawa, Japan.
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Uchiyama
authors.affiliation: Kanazawa University, Graduate School of Medical Science, Division of Neuroscience, Department of Neurosurgery, 13-1 Takara-machi, Kanazawa, 920-8641 Ishikawa, Japan.
authors.forename: Masanao
authors.initials: M
authors.lastname: Mohri
authors.affiliation: Kanazawa University, Graduate School of Medical Science, Division of Neuroscience, Department of Neurosurgery, 13-1 Takara-machi, Kanazawa, 920-8641 Ishikawa, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Hayashi
authors.affiliation: Kanazawa University, Graduate School of Medical Science, Division of Cardiovascular Medicine, Department of Radiology, 13-1 Takara-machi, Kanazawa, 920-8641 Ishikawa, Japan.
authors.forename: Fumiaki
authors.initials: F
authors.lastname: Ueda
authors.affiliation: Kanazawa University, Graduate School of Medical Science, Division of Neuroscience, Department of Neurosurgery, 13-1 Takara-machi, Kanazawa, 920-8641 Ishikawa, Japan.
authors.forename: Mitsutoshi
authors.initials: M
authors.lastname: Nakada
mesh_terms: D000368:Aged; D016893:Carotid Stenosis / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000601:surgery; D000072226:Computed Tomography Angiography / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D058226:Plaque, Atherosclerotic / Q000000981:diagnostic imaging* / Q000473:pathology*; D011183:Postoperative Complications; D012189:Retrospective Studies; D015607:Stents
keywords: Carotid artery stenting; Carotid plaque; In-stent restenosis; Multidetector computed tomography