title: Serial brain MRI in TIA patients.
abstract: OBJECTIVE
  Up to 40% of patients with transient ischemic attack (TIA) demonstrate lesions on diffusion-weighted magnetic resonance imaging (DWI). However, the time course of these ischemic lesions is not well known. Some lesions could vanish soon after symptom onset whereas others could be visible only after a certain delay. Based on a population of TIA patients imaged twice with DWI within the first week after onset, our aim was to estimate the rate of patients with DWI reversible ischemic lesion or with delayed DWI positivity.
  
  
  METHODS
  We retrospectively compared DWI at admission (DWI(1), median = 15 hours after TIA) with follow-up DWI (DWI(2), median = 47 hours) in 64 consecutive TIA over a 7-month period. DWI was reviewed in consensus by two readers, blinded to clinical information. Number, extent and arterial distribution of lesions were assessed.
  
  
  RESULTS
  DWI(1) and DWI(2) showed similar findings in 55 TIA patients (32 with and 23 without ischemic lesions). In nine (14%) patients, changes were observed on DWI(2): presence of ischemic lesions despite normal DWI(1) (n = 3), increase in lesion size (n = 3), or partial or complete lesion reversibility (n = 3).
  
  
  CONCLUSIONS
  In most TIA cases, ischemic lesions captured by early DWI and 48-hour DWI are similar. However, some ischemic lesions vanish rapidly while lesion visibility is delayed in other cases.
authors: Inserm U894, Service d'Imagerie Morphologique et Fonctionnelle, Centre De Psychiatrie et Neurosciences, Centre Hospitalier Sainte-Anne, Université Paris-Descartes, 1 rue Cabanis, 75014 Paris, France.
authors: Nicolas
authors: N
authors: Carpentier
authors: Myriam
authors: M
authors: Edjlali
authors: Fatna
authors: F
authors: Bouhafs
authors: Pauline
authors: P
authors: Roca
authors: David
authors: D
authors: Calvet
authors: Emmanuel
authors: E
authors: Touzé
authors: Jean-Louis
authors: JL
authors: Mas
authors: Jean-François
authors: JF
authors: Méder
authors: Catherine
authors: C
authors: Oppenheim
mesh_terms: D000368:Aged; D001921:Brain / Q000473:pathology*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D002546:Ischemic Attack, Transient / Q000473:pathology*; D008137:Longitudinal Studies; D008297:Male; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013382:Subtraction Technique