title: Feasibility of source images of computed tomographic angiography to detect the extent of ischemia in hyperacute stroke.
abstract: OBJECTIVE
  Computed tomographic angiography (CTA) is suggested to be a promising tool for patient selection for thrombolytic therapy of acute stroke. It does not only provide information on intracranial vasculature, but also on the capacity of the collateral circulation and the pattern of poorly perfused brain tissue. The objective of our study was to evaluate whether the presence and size of critically hypoperfused tissue assessed with flow positron emission tomography (PET) as a gold standard can reliably be identified on CTA source images.
  
  
  METHODS
  Fifteen potential candidates for early thrombolysis underwent CTA 65-170 min (mean 107 min) after the onset of acute anterior circulation stroke. Regional cerebral perfusion was measured between 27 and 86 min (mean 59 min) later with [(15)O]-H(2)O and PET, and the volume of critically hypoperfused cortical tissue was assessed. CTA source images were evaluated by a neuroradiologist and an experienced stroke neurologist. The patients were classified into three groups according to the presumed size of the perfusion deficit on CTA (large, small, no perfusion deficit).
  
  
  RESULTS
  PET revealed the presence of critical cortical hypoperfusion in 10 patients, 5 had no critical cortical hypoperfusion. The neuroradiologist correctly identified the presence of a perfusion deficit in all patients, the neurologist had two false negative and one false positive ratings. Concerning the size of the perfusion deficit, there was considerable inaccuracy in both raters.
  
  
  CONCLUSIONS
  The usefulness of CTA source images in yielding information about the perfusion state of stroke patients in clinical routine should not be overestimated.
authors: Klinik und Poliklinik für Neurologie der Universität zu Köln, Köln, Deutschland.
authors: M
authors: M
authors: Grond
authors: J
authors: J
authors: Rudolf
authors: S
authors: S
authors: Schneweis
authors: K
authors: K
authors: Terstegge
authors: J
authors: J
authors: Sobesky
authors: L
authors: L
authors: Kracht
authors: M
authors: M
authors: Neveling
authors: W-D
authors: WD
authors: Heiss
mesh_terms: D000328:Adult; D000368:Aged; D001157:Arterial Occlusive Diseases / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology; D001783:Blood Flow Velocity / Q000502:physiology; D002545:Brain Ischemia / Q000150:complications* / Q000175:diagnosis* / Q000503:physiopathology; D002536:Cerebral Arteries / Q000000981:diagnostic imaging / Q000473:pathology; D005240:Feasibility Studies; D005260:Female; D005858:Germany; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008297:Male; D008875:Middle Aged; D020521:Stroke / Q000150:complications* / Q000175:diagnosis* / Q000503:physiopathology; D014055:Tomography, Emission-Computed; D014057:Tomography, X-Ray Computed