title: Role of EPI-FLAIR in patients with acute stroke: a comparative analysis with FLAIR.
abstract: OBJECTIVE
  Further improvement in acquisition speed is needed, if MR imaging is to compete with CT for evaluation of patients with acute ischemic stroke. The purpose of this study was to evaluate the feasibility of implementing an echo-planar fluid-attenuated inversion recovery (EPI-FLAIR) sequence into an acute MR stroke protocol with potential reduction in scan time and to compare the results with conventional FLAIR images.
  
  
  METHODS
  Fifty-two patients (28 men and 24 women; age range, 32-96 years) with acute ischemic stroke were prospectively evaluated with an acute stroke MR protocol, which included both conventional FLAIR and EPI-FLAIR imaging with integration of parallel acquisition. The image acquisition time was 52 seconds for EPI-FLAIR and 3 minutes for conventional FLAIR. FLAIR and EPI-FLAIR studies were assessed by 2 observers independently for image quality and conspicuity of hyperintensity in correlation with DWI and were rated as concordant or discordant. Coregistered FLAIR and EPI-FLAIR images were evaluated for signal intensity ratio of the DWI-positive lesion to contralateral normal white matter.
  
  
  RESULTS
  An estimated 96% of all FLAIR and EPI-FLAIR studies were rated of diagnostic image quality by both observers, with interobserver agreements of κ = 0.82 and κ = 0.63 for FLAIR and EPI-FLAIR, respectively. In 36 (95%) of 38 patients with acute infarction, FLAIR and EPI-FLAIR were rated concordant regarding DWI lesion. The mean ± standard deviation of the signal intensity ratio values on EPI-FLAIR and FLAIR for DWI-positive lesions were 1.28 ± 0.16 and 1.25 ± 0.17, respectively (P = .47), and demonstrated significant correlation (r = 0.899, z value = 8.677, P < .0001).
  
  
  CONCLUSIONS
  In patients with acute stroke, EPI-FLAIR is feasible with comparable qualitative and quantitative results to conventional FLAIR and results in reduced acquisition time.
authors: From the Departments of Medical Imaging (A.M., R.K., R.C., K.N.).
authors: A
authors: A
authors: Meshksar
authors: Department of Radiological Sciences (J.P.V.), University of California at Los Angeles, Los Angeles, California.
authors: J P
authors: JP
authors: Villablanca
authors: From the Departments of Medical Imaging (A.M., R.K., R.C., K.N.).
authors: R
authors: R
authors: Khan
authors: From the Departments of Medical Imaging (A.M., R.K., R.C., K.N.).
authors: R
authors: R
authors: Carmody
authors: Neurology (B.C.), University of Arizona; Tucson, Arizona.
authors: B
authors: B
authors: Coull
authors: From the Departments of Medical Imaging (A.M., R.K., R.C., K.N.) kambiz@radiology.arizona.edu.
authors: K
authors: K
authors: Nael
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000473:pathology*; D002545:Brain Ischemia / Q000150:complications / Q000473:pathology*; D056324:Diffusion Tensor Imaging / Q000379:methods*; D017352:Echo-Planar Imaging / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D020521:Stroke / Q000209:etiology / Q000473:pathology*