title: Discriminating carotid atherosclerotic lesion severity by luminal stenosis and plaque burden: a comparison utilizing high-resolution magnetic resonance imaging at 3.0 Tesla.
abstract: OBJECTIVE
  To determine associations between stenosis, measures of plaque burden, and compositional features of carotid atherosclerosis, including high-risk features of intraplaque hemorrhage (IPH) and surface disruption.
  
  
  METHODS
  Institutional Review Board approval and informed consent for all participants were obtained before study initiation. Patients with either carotid stenosis >50% by duplex ultrasound or suspected coronary artery disease underwent multi-contrast carotid MRI at 3.0 T. For each artery, stenosis, percent wall volume (PWV=100%×wall volume/total vessel volume), and mean wall thickness (MWT) were measured. Presence or absence of a lipid-rich necrotic core, calcification, IPH, and surface disruption were recorded.
  
  
  RESULTS
  One hundred eighty-one patients were included in the final analysis. The area under the curve (AUC) calculated from receiver-operating-characteristics analysis found the presence of IPH was similarly classified by stenosis (AUC=0.82), PWV (AUC=0.88), and MWT (AUC=0.88). Notably, IPH was present in the lowest category of each parameter. Prevalence of IPH in arteries with 0% stenosis was 4.4%. In arteries with PWV <40%, prevalence was 3.2%; in arteries with MWT <1.0 mm, prevalence was 2.3%. Strength of classification for surface disruption was similarly classified by stenosis (AUC=0.87), PWV (AUC=0.93), and MWT (AUC=0.94).
  
  
  CONCLUSIONS
  Measures of plaque burden do not substantially improve disease assessment compared to stenosis. The finding of IPH in all categories of stenosis and plaque burden suggests that direct characterization of plaque composition and surface status is necessary to fully discriminate disease severity.
authors.affiliation: Department of Radiology, University of Washington, Seattle, WA 98109, USA.
authors.forename: Xihai
authors.initials: X
authors.lastname: Zhao
authors.forename: Hunter R
authors.initials: HR
authors.lastname: Underhill
authors.forename: Qian
authors.initials: Q
authors.lastname: Zhao
authors.forename: Jianming
authors.initials: J
authors.lastname: Cai
authors.forename: Feiyu
authors.initials: F
authors.lastname: Li
authors.forename: Minako
authors.initials: M
authors.lastname: Oikawa
authors.forename: Li
authors.initials: L
authors.lastname: Dong
authors.forename: Hideki
authors.initials: H
authors.lastname: Ota
authors.forename: Thomas S
authors.initials: TS
authors.lastname: Hatsukami
authors.forename: Baocheng
authors.initials: B
authors.lastname: Chu
authors.forename: Chun
authors.initials: C
authors.lastname: Yuan
mesh_terms: D000368:Aged; D002340:Carotid Artery Diseases / Q000175:diagnosis* / Q000000981:diagnostic imaging; D016893:Carotid Stenosis / Q000175:diagnosis* / Q000000981:diagnostic imaging; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods* / Q000592:standards*; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index; D014463:Ultrasonography