title: Computed tomography workup of patients suspected of acute ischemic stroke: perfusion computed tomography adds value compared with clinical evaluation, noncontrast computed tomography, and computed tomography angiogram in terms of predicting outcome.
abstract: OBJECTIVE
  To determine whether perfusion computed tomography (PCT) adds value to noncontrast head CT (NCT), CT angiogram (CTA), and clinical assessment in patients suspected of acute ischemic stroke.
  
  
  METHODS
  We retrospectively reviewed 165 patients with acute ischemic stroke. PCT was used to calculate the volumes of infarct core and ischemic penumbra on admission. Other imaging data included Alberta Score Program Early CT Score, site of occlusion, and collateral flow. Clinical data included age, time, National Institutes of Health Stroke Scale at baseline, treatment type, and modified Rankin score (mRS) at 90 days. Recanalization status was assessed on follow-up imaging. In a first multivariate regression analysis, we assessed whether volumes of PCT penumbra and infarct core could be predicted from clinical variables, NCT, or CTA, or whether they represented independent information. In a second multivariate regression analysis, we used mRS at 90 days as outcome and determined which variables predicted it best.
  
  
  RESULTS
  Of 165 patients identified, 76 had a mRS score of 0 to 2 at 90 days, 89 had a mRS score >2. PCT infarct could be predicted by clinical data, NCT, CTA, and combinations of this data (P<0.05). PCT penumbra could not be predicted by clinical data, NCT, and CTA. All of the variables but NCT and CTA were significantly associated with 90-day mRS outcome. The single most important predictor was recanalization status (P<0.001). PCT penumbra volume (P=0.001) was also a predictor of clinical outcome, especially when considered in conjunction with recanalization through an interaction term (P<0.001).
  
  
  CONCLUSIONS
  PCT penumbra represents independent information, which cannot be predicted by clinical, NCT, and CTA data. PCT penumbra is an important determinant of clinical outcome and adds relevant clinical information compared with a stroke CT workup, including NCT and CTA.
authors: Department of Radiology, Neuroradiology Division, University of Virginia, Charlottesville, VA 22908, USA.
authors: Guangming
authors: G
authors: Zhu
authors: Patrik
authors: P
authors: Michel
authors: Amin
authors: A
authors: Aghaebrahim
authors: James T
authors: JT
authors: Patrie
authors: Wenjun
authors: W
authors: Xin
authors: Ashraf
authors: A
authors: Eskandari
authors: Weiwei
authors: W
authors: Zhang
authors: Max
authors: M
authors: Wintermark
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000792:Angiography / Q000379:methods; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007511:Ischemia / Q000175:diagnosis / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D010477:Perfusion; D012044:Regression Analysis; D012189:Retrospective Studies; D020521:Stroke / Q000175:diagnosis / Q000473:pathology*; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000379:methods*; D016896:Treatment Outcome