title: Fluid-attenuated inversion recovery (FLAIR) sequences for the assessment of acute stroke: inter observer and inter technique reproducibility.
abstract: OBJECTIVE
  Diffusion-weighted magnetic resonance (MR) imaging (DWI), and three-dimensional (3D) time-of-flight (TOF) MR angiography (MRA), are highly sensitive for the early detection of stroke and arterial occlusion. However, only a few studies have evaluated the sensitivity of conventional MR sequences that are usually included in the imaging protocol. The aim of this study was to evaluate interobserver and intertechnique reproducibility of Fluid-Attenuated Inversion Recovery (FLAIR) sequences for the diagnosis of early brain ischemia and arterial occlusion.
  
  
  METHODS
  Over a 30-month period, brain MR examinations were performed in 34 patients within 12 hours after stroke onset. Imaging protocol included FLAIR sequences, DWI and 3D TOF MRA. Ten observers including radiologists and neurologists, performed separately a visual interpretation of FLAIR images for the detection of brain ischemia and arterial occlusion seen as an arterial high signal. DWI and 3D TOF MRA were used as reference and interpreted independently by two senior radiologists. Interobserver agreement was assessed for image quality, detectability and conspicuity of lesions whereas intertechnique agreement was only judged for lesion detectability.
  
  
  RESULTS
  On FLAIR sequences, interobserver agreement for the detection of brain ischemia and arterial occlusion was excellent (kappa = 0.81 and 0.87 respectively). The concordance between FLAIR and DWI sequences for the detection of brain ischemia and between FLAIR and 3D TOF MRA for the detection of arterial occlusion were judged as excellent for all observers (kappa = 0.91 and 0.89 respectively).
  
  
  CONCLUSIONS
  Although DWI is the most sensitive technique with which to detect acute stroke, FLAIR imaging may also be useful to demonstrate both acute ischemia and arterial occlusion with an excellent interobserver reproducibility.
authors.affiliation: Service de Neuroradiologie, Hôpital Roger Salengro, Rue Emile Laine, 59037, Lille Cedex, France. jygauvrit@chru-lille.fr
authors.forename: Jean-Yves
authors.initials: JY
authors.lastname: Gauvrit
authors.forename: Xavier
authors.initials: X
authors.lastname: Leclerc
authors.forename: Marie
authors.initials: M
authors.lastname: Girot
authors.forename: Charlotte
authors.initials: C
authors.lastname: Cordonnier
authors.forename: Gustavo
authors.initials: G
authors.lastname: Sotoares
authors.forename: Hilde
authors.initials: H
authors.lastname: Henon
authors.forename: Bruno
authors.initials: B
authors.lastname: Pertuzon
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Michelin
authors.forename: David
authors.initials: D
authors.lastname: Devos
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Pruvo
authors.forename: Didier
authors.initials: D
authors.lastname: Leys
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D018810:Magnetic Resonance Angiography; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D020521:Stroke / Q000175:diagnosis*