title: T1-weighted fluid-attenuated inversion recovery at low field strength: a viable alternative for T1-weighted intracranial imaging.
abstract: OBJECTIVE
  T1-weighted spin-echo imaging has been widely used to study anatomic detail and abnormalities of the brain; however, the image contrast of this technique is often poor, especially at low field strengths. We tested a new pulse sequence, T1-weighted fluid-attenuated inversion recovery (FLAIR), which provides good contrast between lesions, surrounding edematous tissue, and normal parenchyma at low field strengths and at acquisition times comparable to those of T1-weighted spin-echo imaging.
  
  
  METHODS
  Thirteen patients with brain lesions underwent T1-weighted spin-echo and T1-weighted FLAIR imaging during the same imaging session. T1-weighted spin-echo and T1-weighted FLAIR images were compared on the basis of four quantitative (lesion-white matter [WM] contrast-to-noise ratio [CNR], lesion-CSF CNR, gray matter-WM CNR, and WM-CSF CNR) and three qualitative criteria (conspicuousness of lesions, image artifacts, and overall image contrast).
  
  
  RESULTS
  CNRs obtained with T1-weighted FLAIR were comparable but statistically superior to those obtained with T1-weighted spin-echo imaging. In general, T1-weighted FLAIR and T1-weighted spin-echo imaging produced comparable image artifacts. Conspicuousness of lesions and the overall image contrast were judged to be superior on T1-weighted FLAIR images.
  
  
  CONCLUSIONS
  T1-weighted FLAIR imaging may be a valuable alternative to conventional T1-weighted imaging, because the former technique offers superior image contrast at low field strengths and comparable acquisition times.
authors.affiliation: Department of Radiology, Yamanashi Medical University, Nakakoma-gun, Tamanashi, Japan.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Hori
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Okubo
authors.forename: Kazuhito
authors.initials: K
authors.lastname: Uozumi
authors.forename: Keiichi
authors.initials: K
authors.lastname: Ishigame
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kumagai
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Araki
mesh_terms: D000328:Adult; D000368:Aged; D001921:Brain / Q000473:pathology; D001927:Brain Diseases / Q000175:diagnosis* / Q000473:pathology; D001929:Brain Edema / Q000175:diagnosis / Q000473:pathology; D001932:Brain Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000556:secondary; D006528:Carcinoma, Hepatocellular / Q000175:diagnosis / Q000473:pathology / Q000556:secondary; D002544:Cerebral Infarction / Q000175:diagnosis / Q000473:pathology; D003937:Diagnosis, Differential; D005260:Female; D005909:Glioblastoma / Q000175:diagnosis / Q000473:pathology; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008113:Liver Neoplasms / Q000175:diagnosis / Q000473:pathology; D008175:Lung Neoplasms / Q000175:diagnosis / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008577:Meningeal Neoplasms / Q000175:diagnosis / Q000473:pathology; D008579:Meningioma / Q000175:diagnosis / Q000473:pathology; D008581:Meningitis / Q000175:diagnosis / Q000473:pathology; D008875:Middle Aged; D009463:Neuroma / Q000175:diagnosis / Q000473:pathology; D012680:Sensitivity and Specificity