title: Hyperacute diffusion-weighted imaging abnormalities in transient ischemic attack patients signify irreversible ischemic infarction.
abstract: BACKGROUND
  To characterize the frequency and clinical features of diffusion-weighted imaging (DWI) abnormalities in the hyperacute phase of transient ischemic attacks (TIAs).
  
  
  METHODS
  We performed DWI in 21 consecutive patients with TIA (mean age 64 years; 17 men and 4 women) during both the hyperacute phase (within 6 h after onset) and subacute phase (within 2-9 days after onset).
  
  
  RESULTS
  DWI abnormalities were present in the hyperacute phase in 11 patients (positive group) and absent in the other 10 patients (negative group). These groups could not be differentiated based on the clinical characteristics. In the subacute phase, all 11 patients from the positive group had abnormalities on MRI including T2-weighted and fluid attenuation inversion recovery images as well as DWI, with lesions being located in regions similar to those observed in the hyperacute phase. Of the 10 patients in the negative group, new DWI abnormalities were noted in 2 during the subacute phase.
  
  
  CONCLUSIONS
  Approximately half of TIA patients in whom MRI was performed in the hyperacute phase had DWI abnormalities, all of which persisted in the subacute phase. The findings suggest that essentially all hyperacute DWI abnormalities in TIA patients may indicate irreversibility and signify the presence of brain infarction.
authors.affiliation: Stroke Center, Saiseikai Kumamoto Hospital, Kumamoto, Japan. inatomi@skh.saiseikai.or.jp
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Inatomi
authors.forename: Kazumi
authors.initials: K
authors.lastname: Kimura
authors.forename: Toshiro
authors.initials: T
authors.lastname: Yonehara
authors.forename: Shodo
authors.initials: S
authors.lastname: Fujioka
authors.forename: Makoto
authors.initials: M
authors.lastname: Uchino
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001018:Aortic Diseases / Q000150:complications; D002545:Brain Ischemia / Q000473:pathology*; D002544:Cerebral Infarction / Q000473:pathology*; D038524:Diffusion Magnetic Resonance Imaging; D004617:Embolism / Q000150:complications; D005260:Female; D006331:Heart Diseases / Q000150:complications; D006801:Humans; D007091:Image Processing, Computer-Assisted; D002546:Ischemic Attack, Transient / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D010291:Paresis / Q000209:etiology; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors