title: Intracranial Plaque Characterization in Patients with Acute Ischemic Stroke Using Pre- and Post-Contrast Three-Dimensional Magnetic Resonance Vessel Wall Imaging.
abstract: BACKGROUND
  Magnetic resonance vessel wall imaging (VWI) techniques have been developed to assess atherosclerotic plaques in intracranial arteries, which are a cardinal cause of ischemic stroke. However, the clinical roles of plaque-related vulnerability and inflammation remain unclear. Hence, we evaluated plaque characteristics using VWI of the proximal middle cerebral artery (M1) in patients with acute ischemic stroke.
  
  
  METHODS
  We prospectively examined 30 consecutive patients with acute noncardioembolic stroke in the M1 territory using pre-/postcontrast T1-weighted (T1W) three-dimensional (3D) VWI with a 3-Tesla scanner. The contrast ratio (CR) and contrast enhancement of the plaques were measured bilaterally at M1.
  
  
  RESULTS
  Plaques were identified in the bilateral M1s of all patients, and no substantial stenosis existed. The M1 plaque CRs ipsilateral to the infarct (46.7%-67.9%) were significantly higher than the plaque CRs on the contralateral side (34.3%-69.4%), particularly in patients with lacunar infarcts (P <.01). In contrast, the occurrence of plaque enhancement was not different between the ipsilateral (20.0%) and contralateral (16.7%) sides. Further, the CRs in the nonlacunar group were significantly higher than the CRs in the lacunar group (P <.05), whereas enhanced plaques tended to be more frequent in the nonlacunar group, but this difference was not significant (P = .09).
  
  
  CONCLUSIONS
  T1W 3D-VWI revealed that the signal intensity of M1 plaques was significantly higher in the affected side and in nonlacunar-type infarcts of patients with acute stroke, suggesting that unstable plaques in the M1 can cause stroke events presumably due to atherothrombotic mechanisms.
authors.affiliation: Department of Neurology and Gerontology, Iwate Medical University, Japan. Electronic address: tnatori@iwate-med.ac.jp.
authors.forename: Tatsunori
authors.initials: T
authors.lastname: Natori
authors.affiliation: Division of Ultrahigh Field MRI, Institute for Biomedical Sciences, Iwate Medical University, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Sasaki
authors.affiliation: GE Healthcare, Japan.
authors.forename: Mitsuharu
authors.initials: M
authors.lastname: Miyoshi
authors.affiliation: Department of Neurology and Gerontology, Iwate Medical University, Japan.
authors.forename: Kohei
authors.initials: K
authors.lastname: Ito
authors.affiliation: Department of Neurology and Gerontology, Iwate Medical University, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Ohba
authors.affiliation: Department of Neurology and Gerontology, Iwate Medical University, Japan.
authors.forename: Haruna
authors.initials: H
authors.lastname: Miyazawa
authors.affiliation: Department of Neurology and Gerontology, Iwate Medical University, Japan.
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Narumi
authors.affiliation: GE Healthcare, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kabasawa
authors.affiliation: Division of Ultrahigh Field MRI, Institute for Biomedical Sciences, Iwate Medical University, Japan.
authors.forename: Taisuke
authors.initials: T
authors.lastname: Harada
authors.affiliation: Department of Neurology and Gerontology, Iwate Medical University, Japan.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Terayama
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002545:Brain Ischemia / Q000000981:diagnostic imaging*; D002533:Cerebral Angiography / Q000379:methods*; D003287:Contrast Media / Q000008:administration & dosage*; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D019786:Gadolinium DTPA / Q000008:administration & dosage*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D021621:Imaging, Three-Dimensional; D020244:Infarction, Middle Cerebral Artery / Q000000981:diagnostic imaging*; D002537:Intracranial Arteriosclerosis / Q000000981:diagnostic imaging*; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging*; D058226:Plaque, Atherosclerotic; D011237:Predictive Value of Tests; D011446:Prospective Studies; D059409:Stroke, Lacunar / Q000000981:diagnostic imaging*
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA
keywords: MRI; Vessel wall imaging; atherosclerosis; stroke