title: High-intensity signal on time-of-flight magnetic resonance angiography indicates carotid plaques at high risk for cerebral embolism during stenting.
abstract: OBJECTIVE
  A major disadvantage of carotid artery stenting (CAS) compared to carotid endarterectomy is the increased risk of cerebral embolism. Thus, establishing a simple method to discriminate fragile plaques on preoperative routine examination is important. The present study examined whether high-intensity signal (HIS) in the plaque on time-of-flight (TOF) MRA, performed for screening, can discriminate plaque at high risk for cerebral embolism during CAS.
  
  
  METHODS
  In the 30 patients treated using carotid endarterectomy, relationships between pathological findings of the plaques and TOF-MRA findings were analyzed. In the 112 patients treated using CAS, postoperative ipsilateral ischemic lesions on diffusion-weighted imaging and periprocedural ischemic symptoms were analyzed.
  
  
  RESULTS
  The percentage area of intraplaque hemorrhage stained by glycophorin A was significantly larger in HIS-positive plaques (51.8%±9.8%) than in HIS-negative plaques (8.6%±9.4%; P<0.001). Postoperative ischemic lesions on diffusion-weighted imaging were more frequent in the HIS-positive plaques (25/38; 65.8%) than in the HIS-negative plaques (26/74; 35.1%; P=0.002). Periprocedural ischemic symptoms were more frequently observed in HIS-positive plaques (7/38; 18.4%) than in HIS-negative plaques (1/74; 1.4%; P=0.003). Multivariate logistic regression analysis identified HIS on TOF-MRA as an independent predictor of periprocedural ischemic symptoms (odds ratio, 15.08; 95% confidence interval, 1.76-129.0).
  
  
  CONCLUSIONS
  HIS in the plaque on TOF-MRA performed for screening could discriminate plaques at high risk for cerebral embolism during CAS.
authors.affiliation: Department of Neurosurgery, Graduate School of Medicine, Gifu University, Yanagido, Gifu city, Gifu 501-1194, Japan. shinichiyoshimura@hotmail.com
authors.forename: Shinichi
authors.initials: S
authors.lastname: Yoshimura
authors.forename: Kiyofumi
authors.initials: K
authors.lastname: Yamada
authors.forename: Masanori
authors.initials: M
authors.lastname: Kawasaki
authors.forename: Takahiko
authors.initials: T
authors.lastname: Asano
authors.forename: Masayuki
authors.initials: M
authors.lastname: Kanematsu
authors.forename: Manabu
authors.initials: M
authors.lastname: Takamatsu
authors.forename: Akira
authors.initials: A
authors.lastname: Hara
authors.forename: Toru
authors.initials: T
authors.lastname: Iwama
mesh_terms: D000368:Aged; D016893:Carotid Stenosis / Q000000981:diagnostic imaging* / Q000601:surgery*; D005260:Female; D006801:Humans; D020766:Intracranial Embolism / Q000000981:diagnostic imaging* / Q000209:etiology; D007431:Intraoperative Complications / Q000000981:diagnostic imaging* / Q000209:etiology; D018810:Magnetic Resonance Angiography / Q000379:methods; D008297:Male; D008875:Middle Aged; D011859:Radiography; D012189:Retrospective Studies; D012307:Risk Factors; D015607:Stents / Q000009:adverse effects*