title: Functional image of dynamic computed tomography in diagnostic and prognostic evaluation of ischemic stroke within the first 6 hours.
abstract: OBJECTIVE
  It is important to make a diagnosis before a low-density area appears on computed tomography for appropriate management of acute ischemic stroke. We report the diagnostic and prognostic usefulness of functional image of dynamic computed tomography for acute ischemic stroke.
  
  
  METHODS
  Forty-seven patients with ischemic strokes within 6 hours of ictus underwent dynamic computed tomography in which functional images were obtained. These findings were compared with angiographic findings, follow-up computed tomography, and clinical outcome.
  
  
  RESULTS
  The functional images were categorized into three groups: (1) cortical type: abnormalities on time to peak image and/or corrected mean transit time image involving mainly cortical structures (29 cases); (2) noncortical type: abnormalities on either or both images limited to noncortical structures (7 cases); and (3) normal type: no abnormalities on both images (11 cases). Cortical type as a diagnostic test for arterial trunk occlusion had a good sensitivity (100%), specificity (95%), and accuracy (98%). Infarction volume on follow-up computed tomography correlated with extension of prolonged time-to-peak area (r = .80, P < .01) and that of prolonged corrected mean transit time area (r = .81, P < .01). Cortical type was associated with significantly unfavorable outcome (P < .01).
  
  
  CONCLUSIONS
  Functional image of dynamic computed tomography findings predicted arterial trunk occlusion, infarction volume, and clinical outcome. Therefore, this technique would be useful not only for indicating definitive angiography and subsequent therapy but for evaluating the effectiveness of surgical or medical recanalization.
authors.affiliation: Department of Neurosurgery, Shinshu University School of Medicine, Matsumoto, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Toriyama
authors.forename: Y
authors.initials: Y
authors.lastname: Tanizaki
authors.forename: K
authors.initials: K
authors.lastname: Hongo
authors.forename: M
authors.initials: M
authors.lastname: Osawa
authors.forename: S
authors.initials: S
authors.lastname: Kobayashi
mesh_terms: D000208:Acute Disease; D000368:Aged; D002545:Brain Ischemia / Q000175:diagnosis*; D002533:Cerebral Angiography; D002540:Cerebral Cortex / Q000098:blood supply; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D011379:Prognosis; D012039:Regional Blood Flow; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000379:methods*