title: Subacute and chronic subarachnoid hemorrhage: diagnosis with fluid-attenuated inversion-recovery MR imaging.
abstract: OBJECTIVE
  To evaluate fluid-attenuated inversion-recovery (FLAIR) magnetic resonance (MR) imaging in the detection of subacute and chronic subarachnoid hemorrhage.
  
  
  METHODS
  The authors performed 19 FLAIR MR imaging examinations at 0.5 T in 14 adult patients with subarachnoid hemorrhage 3-45 days after the ictus and 22 FLAIR examinations in 22 adult control subjects. The detection of subacute and chronic subarachnoid hemorrhage on FLAIR images was compared with the detection on conventional spin-echo MR and computed tomographic (CT) images.
  
  
  RESULTS
  In the detection of subacute subarachnoid hemorrhage, FLAIR (100% detection) was significantly superior to T1-weighted imaging (36% detection, P < .01), T2-weighted imaging (0% detection, P < .02), and CT (45% detection, P < .02 [Fisher exact test]). Although FLAIR imaging (63% detection) was superior in chronic subarachnoid hemorrhage detection, there were no statistically significant differences between modalities. FLAIR imaging demonstrated all subarachnoid hemorrhage areas as high-signal-intensity areas within 18 days and up to a maximum of 45 days after the ictus. In a blind comparison, no FLAIR images acquired in control subjects were confused with those acquired in patients.
  
  
  CONCLUSIONS
  FLAIR diagnostic images are superior to conventional MR or CT images in patients with subacute subarachnoid hemorrhage.
authors.affiliation: Department of Radiology, Toyama Medical and Pharmaceutical University, Toyama City, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Noguchi
authors.forename: T
authors.initials: T
authors.lastname: Ogawa
authors.forename: H
authors.initials: H
authors.lastname: Seto
authors.forename: A
authors.initials: A
authors.lastname: Inugami
authors.forename: H
authors.initials: H
authors.lastname: Hadeishi
authors.forename: H
authors.initials: H
authors.lastname: Fujita
authors.forename: J
authors.initials: J
authors.lastname: Hatazawa
authors.forename: E
authors.initials: E
authors.lastname: Shimosegawa
authors.forename: T
authors.initials: T
authors.lastname: Okudera
authors.forename: K
authors.initials: K
authors.lastname: Uemura
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D001921:Brain / Q000000981:diagnostic imaging / Q000473:pathology; D002908:Chronic Disease; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D013345:Subarachnoid Hemorrhage / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000209:etiology; D014057:Tomography, X-Ray Computed