title: Improvement of sensitivity and interrater reliability to detect acute stroke by dynamic perfusion computed tomography and computed tomography angiography.
abstract: OBJECTIVE
  To assess the benefits of additional computed tomography perfusion (CTP) and computed tomography angiography (CTA) on the detection of early stroke, vessel occlusion, estimated infarct size, and interrater reliability.
  
  
  METHODS
  Sixty-seven consecutive patients underwent nonenhanced computed tomography (CT) imaging, CTA, and CTP. The final diagnosis of stroke was made from follow-up neuroimaging. A first diagnosis was made on-site by the physician on duty. Three experienced neuroradiologists blinded to follow-up findings analyzed the data set off-line, evaluated CT for signs of acute stroke, and subsequently evaluated CTP and CTA for infarction-related perfusion deficits and vessel abnormalities.
  
  
  RESULTS
  Computed tomography perfusion and CTA increased the time from CT start to diagnosis from 2 minutes to 10 minutes. Sensitivity to detect acute stroke increased significantly in all investigators from 0.46-0.58 to 0.79-0.90 compared with CT (<0.005). The interrater weighted kappa value increased from 0.35 to 0.64. Estimation of infarct size was not improved.
  
  
  CONCLUSIONS
  Computed tomography perfusion and CTA provide an effective add-on to standard CT in acute stroke imaging by significantly increasing the sensitivity and reliability of infarct detection.
authors.affiliation: Department of Neuroradiology, University Hospital Mannheim, Mannheim, Germany. johann.scharf@rad.ma.uni-heidelberg.de
authors.forename: Johann
authors.initials: J
authors.lastname: Scharf
authors.forename: Marc A
authors.initials: MA
authors.lastname: Brockmann
authors.forename: Michael
authors.initials: M
authors.lastname: Daffertshofer
authors.forename: Michael
authors.initials: M
authors.lastname: Diepers
authors.forename: Eva
authors.initials: E
authors.lastname: Neumaier-Probst
authors.forename: Christel
authors.initials: C
authors.lastname: Weiss
authors.forename: Tilmann
authors.initials: T
authors.lastname: Paschke
authors.forename: Christoph
authors.initials: C
authors.lastname: Groden
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002533:Cerebral Angiography / Q000379:methods*; D002560:Cerebrovascular Circulation; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D020521:Stroke / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed / Q000379:methods*