title: Thrombus localization with emergency cerebral CT.
abstract: OBJECTIVE
  To determine the prevalence of the hyperdense middle cerebral artery sign (HMCAS) in an acute stroke population (treated with intravenous tissue plasminogen activator (tPA) within 90 minutes of stroke onset); to correlate the presence/absence of the sign with arteriographic findings; and to correlate the HMCAS with the volume of subsequent infarction.
  
  
  METHODS
  55 patients with acute ischemic stroke underwent CT to exclude cerebral hemorrhage and were then treated with intravenous tPA. The neuroradiologist, blinded to the clinical and arteriographic data, sought the HMCAS on the initial and subsequent scans.
  
  
  RESULTS
  The HMCAS was detected by CT in 19 of 55 (34.5%) patients (one false positive). Arteriograms in 14 of the 18 true positive patients confirmed the CT-predicted middle cerebral artery segment in 12. The 18 patients developed infarcts larger than patients not exhibiting the sign (132 cc vs 52 cc, P less than .002).
  
  
  CONCLUSIONS
  The HMCAS does predict middle cerebral artery occlusion and subsequent development of a large infarct.
authors.affiliation: Department of Radiology, University of Cincinnati, OH 45267-0742.
authors.forename: T
authors.initials: T
authors.lastname: Tomsick
authors.forename: T
authors.initials: T
authors.lastname: Brott
authors.forename: W
authors.initials: W
authors.lastname: Barsan
authors.forename: J
authors.initials: J
authors.lastname: Broderick
authors.forename: E C
authors.initials: EC
authors.lastname: Haley
authors.forename: J
authors.initials: J
authors.lastname: Spilker
mesh_terms: D002545:Brain Ischemia / Q000000981:diagnostic imaging / Q000188:drug therapy*; D006801:Humans; D002542:Intracranial Embolism and Thrombosis / Q000000981:diagnostic imaging*; D013997:Time Factors; D010959:Tissue Plasminogen Activator / Q000627:therapeutic use*; D014057:Tomography, X-Ray Computed
chemical_list: D010959:Tissue Plasminogen Activator