title: The extent of perfusion deficit does not relate to the visibility of acute ischemic lesions on fluid-attenuated inversion recovery imaging.
abstract: OBJECTIVE
  Fluid-attenuated inversion recovery imaging (FLAIR) has been suggested as a surrogate marker of lesion age in acute ischemic stroke. In a subgroup analysis, we evaluated whether the extent of perfusion deficit influences FLAIR lesion visibility and thus plays a role as a confounding variable in the interpretation of FLAIR images.
  
  
  METHODS
  A subgroup of patients from a previous study evaluating the use of FLAIR imaging as a surrogate marker of lesion age within the first 6 hours of ischemic stroke were examined to determine the influence of the amount of perfusion deficit on FLAIR lesion visibility.
  
  
  RESULTS
  N = 48 patients were included into the analysis. In positive and negative FLAIR lesion cases the extent of perfusion deficits did not differ significantly (150 mL vs. 197 mL, P = .730) nor influenced FLAIR visibility independently. In contrast, diffusion weighted imaging (DWI) lesion volumes were larger (34 mL vs. 14 mL, P = .008) and time from symptom onset longer (180 vs. 120 minute, P = .071) in FLAIR-positive cases.
  
  
  CONCLUSIONS
  Visibility of FLAIR lesions in acute stroke imaging is influenced by lesion size and time from symptom onset to MRI, but not by the amount of perfusion deficit calculated by time-to-peak (TTP) measurements.
authors: Klinik und Poliklinik für Neurologie, Kopf- und Neurozentrum, Universitätsklinikum Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg, Germany. b.cheng@uke.uni-hamburg.de
authors: Bastian
authors: B
authors: Cheng
authors: Michael
authors: M
authors: Rosenkranz
authors: Anna
authors: A
authors: Krützelmann
authors: Jens
authors: J
authors: Fiehler
authors: Nils D
authors: ND
authors: Forkert
authors: Christian
authors: C
authors: Gerloff
authors: Götz
authors: G
authors: Thomalla
mesh_terms: D000368:Aged; D000465:Algorithms; D001921:Brain / Q000473:pathology*; D002545:Brain Ischemia / Q000473:pathology*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity