title: Prognostic value of cerebral perfusion-computed tomography in the acute stage after subarachnoid hemorrhage for the development of delayed cerebral ischemia.
abstract: OBJECTIVE
  Delayed cerebral ischemia (DCI) is an important cause of death and disability after subarachnoid hemorrhage. We studied the additional prognostic value of brain perfusion to 3 established predictors (age, clinical condition on admission, and amount of subarachnoid blood) for the development of DCI.
  
  
  METHODS
  We included 69 patients scanned with perfusion--computed tomography within 72 hours after subarachnoid hemorrhage. For each patient, we determined cerebral blood flow (CBF) ratios of prespecified opposite regions of interest and the 3 established predictors. We calculated adjusted hazard ratios (HRs) for the CBF ratio and the 3 established predictors by means of multivariate analysis (Cox regression). The additional prognostic value of CBF ratios was assessed by comparing the area under the receiver operating characteristic curve (AUC) of 2 models: 1 with and 1 without addition of the CBF ratio to the 3 established predictors.
  
  
  RESULTS
  The CBF ratio was an independent predictor for the development of DCI (HR, 0.63; 95% CI, 0.46 to 0.86) as was clinical condition (HR, 1.47; 95% CI, 1.01 to 2.13). By adding the CBF ratio to the model with the 3 established predictors, the AUC of the receiver operating characteristic curve increased from 0.76 (95% CI, 0.65 to 0.89) to 0.81 (95% CI, 0.71 to 0.91). This trend toward an increased AUC suggests an improved predictive value.
  
  
  CONCLUSIONS
  The CBF ratio is an independent predictor for the development of DCI and can contribute to a better identification of patients at high risk for DCI.
authors.affiliation: Department of Radiology, University Medical Centre, Utrecht, The Netherlands. i.vanderschaaf@rrr.azu.nl
authors.forename: Irene
authors.initials: I
authors.lastname: van der Schaaf
authors.forename: Marieke J
authors.initials: MJ
authors.lastname: Wermer
authors.forename: Yolanda
authors.initials: Y
authors.lastname: van der Graaf
authors.forename: Birgitta K
authors.initials: BK
authors.lastname: Velthuis
authors.forename: Clemens I B
authors.initials: CI
authors.lastname: van de Kraats
authors.forename: Gabriel J E
authors.initials: GJ
authors.lastname: Rinkel
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D019540:Area Under Curve; D002545:Brain Ischemia / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010477:Perfusion; D010865:Pilot Projects; D011379:Prognosis; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D013345:Subarachnoid Hemorrhage / Q000175:diagnosis*; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000379:methods*; D016896:Treatment Outcome