title: A noninvasive imaging approach to assess plaque severity: the carotid atherosclerosis score.
abstract: OBJECTIVE
  The presence of IPH and/or FCR in the carotid atherosclerotic plaque indicates a high-risk lesion. The aim of this multicenter cross-sectional study was to establish the characteristics of lesions that may precede IPH and/or FCR. We further sought to construct a CAS that stratifies carotid disease severity.
  
  
  METHODS
  Three hundred forty-four individuals from 4 imaging centers with 16%-99% carotid stenosis by duplex sonography underwent carotid MR imaging. In approximately 60% of the study sample (training group), multivariate analysis was used to determine factors associated with IPH and FCR. Statistically significant parameters identified during multivariate analysis were used to construct CAS. CAS was then applied to the remaining arteries (40%, test group), and the accuracy of classification for determining the presence versus absence of IPH or, separately, FCR was determined by ROC analysis and calculation of the AUC.
  
  
  RESULTS
  The maximum proportion of the arterial wall occupied by the LRNC was the strongest predictor of IPH (P < .001) and FCR (P < .001) during multivariate analysis of the training group. The subsequently derived CAS applied to the test group was an accurate classifier of IPH (AUC = 0.91) and FCR (AUC = 0.93). Compared with MRA stenosis, CAS was a stronger classifier of both IPH and FCR.
  
  
  CONCLUSIONS
  LRNC quantification may be an effective complementary strategy to stenosis for classifying carotid atherosclerotic disease severity. CAS forms the foundation for a simple imaging-based risk-stratification system in the carotid artery to classify severity of atherosclerotic disease.
authors.affiliation: Department of Radiology, Vascular Imaging Lab, University of Washington, 815 Mercer Street, Seattle, WA 98109, USA. hunterru@u.washington.edu
authors.forename: H R
authors.initials: HR
authors.lastname: Underhill
authors.forename: T S
authors.initials: TS
authors.lastname: Hatsukami
authors.forename: J
authors.initials: J
authors.lastname: Cai
authors.forename: W
authors.initials: W
authors.lastname: Yu
authors.forename: J K
authors.initials: JK
authors.lastname: DeMarco
authors.forename: N L
authors.initials: NL
authors.lastname: Polissar
authors.forename: H
authors.initials: H
authors.lastname: Ota
authors.forename: X
authors.initials: X
authors.lastname: Zhao
authors.forename: L
authors.initials: L
authors.lastname: Dong
authors.forename: M
authors.initials: M
authors.lastname: Oikawa
authors.forename: C
authors.initials: C
authors.lastname: Yuan
mesh_terms: D000368:Aged; D002339:Carotid Arteries / Q000000981:diagnostic imaging / Q000473:pathology*; D002340:Carotid Artery Diseases / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000473:pathology*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D015995:Prevalence; D012372:ROC Curve; D012307:Risk Factors; D012720:Severity of Illness Index; D018616:Ultrasonography, Doppler, Duplex