title: Do transient ischemic attacks with diffusion-weighted imaging abnormalities correspond to brain infarctions?
abstract: OBJECTIVE
  Our aim was to determine whether diffusion-weighted imaging (DWI) changes associated with transient ischemic attack (TIA) are reversible or correspond to permanent tissue injury.
  
  
  METHODS
  Among 103 consecutive patients admitted for TIA, 36 (34.9%) had abnormalities on initial DWI (delay from TIA = 30 +/- 33 hours [mean +/- SD]). Thirty-three patients (59 DWI lesions) had an MR imaging follow-up (delay from TIA = 10.6 +/- 5 months) including fluid-attenuated inversion recovery, T2, DWI, and 3D T1-weighted sequences. For each lesion, we recorded the quantitative parameters on initial DWI (volume, apparent diffusion coefficient [ADC]) and performed a comparison between reversible and irreversible lesions.
  
  
  RESULTS
  MR imaging failed to detect any permanent injury in 7 patients and identified subsequent infarct in regions corresponding to the original DWI abnormalities in 26 patients (79%). Of the 59 lesions initially identified on DWI, 45 (76.3%) were associated with permanent injury on follow-up MR imaging. The DWI volume was significantly larger (0.91 +/- 1.7 versus 0.21 +/- 0.21 cm(3), P = .003) and the ADC ratio values lower (79 +/- 15% versus 91 +/- 9%, P = .001) in lesions with subsequent infarct than in those that were fully reversible.
  
  
  CONCLUSIONS
  By showing that most patients with DWI-positive TIAs share the same imaging outcome as stroke patients, our data provide additional support for the redefinition of TIA, which considers that all cases of transient deficit with characteristic neuroimaging abnormalities should be diagnosed as a stroke.
authors.affiliation: Department of Neuroradiology, Université Paris Descartes, Centre Hospitalier Sainte-Anne, Paris, France. c.oppenheim@ch-sainte-anne.fr
authors.forename: C
authors.initials: C
authors.lastname: Oppenheim
authors.forename: C
authors.initials: C
authors.lastname: Lamy
authors.forename: E
authors.initials: E
authors.lastname: Touzé
authors.forename: D
authors.initials: D
authors.lastname: Calvet
authors.forename: M
authors.initials: M
authors.lastname: Hamon
authors.forename: J-L
authors.initials: JL
authors.lastname: Mas
authors.forename: J-F
authors.initials: JF
authors.lastname: Méder
mesh_terms: D000328:Adult; D000368:Aged; D001925:Brain Damage, Chronic / Q000175:diagnosis; D002544:Cerebral Infarction / Q000175:diagnosis*; D003937:Diagnosis, Differential; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted; D002546:Ischemic Attack, Transient / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D011379:Prognosis