title: Evaluating CT perfusion using outcome measures of delayed cerebral ischemia in aneurysmal subarachnoid hemorrhage.
abstract: OBJECTIVE
  DCI is a serious complication following aneurysmal SAH and remains a leading cause of morbidity and mortality. Our aim was to evaluate CTP in aneurysmal SAH by using outcome measures of DCI.
  
  
  METHODS
  This was a retrospective study of consecutive patients with SAH enrolled in a prospective institutional review board-approved clinical accuracy trial. Qualitative CTP deficits were determined by 2 neuroradiologists blinded to clinical and imaging data. Quantitative CTP was performed by using a standardized protocol with region-of-interest placement sampling of the cortex. Primary outcome measures were permanent neurologic deficits and infarction. The secondary outcome measure was DCI, defined as clinical deterioration. CTP test characteristics (95% CI) were determined for each outcome measure. Statistical significance was calculated by using the Fisher exact and Student t tests. ROC curves were generated to determine accuracy and threshold analysis.
  
  
  RESULTS
  Ninety-six patients were included. Permanent neurologic deficits developed in 33% (32/96). CTP deficits were seen in 78% (25/32) of those who developed permanent neurologic deficits and 34% (22/64) of those without (P < .0001). CTP deficits had 78% (61%-89%) sensitivity, 66% (53%-76%) specificity, and 53% (39%-67%) positive and 86% (73%-93%) negative predictive values. Infarction occurred in 18% (17/96). CTP deficits were seen in 88% (15/17) of those who developed infarction and 41% (32/79) of those without (P = .0004). CTP deficits had an 88% (66%-97%) sensitivity, 59% (48%-70%) specificity, and 32% (20%-46%) positive and 96% (86%-99%) negative predictive values. DCI was diagnosed in 50% (48/96). CTP deficits were seen in 81% (39/48) of patients with DCI and in 17% (8/48) of those without (P < .0001). CTP deficits had 81% (68%-90%) sensitivity, 83% (70%-91%) specificity, and 83% (70%-91%) positive and 82% (69%-90%) negative predictive values. Quantitative CTP revealed significantly reduced CBF and prolonged MTT for DCI, permanent neurologic deficits, and infarction. ROC analysis showed that CBF and MTT had the highest accuracy.
  
  
  CONCLUSIONS
  CTP may add prognostic information regarding DCI and poor outcomes in aneurysmal SAH.
authors.affiliation: Departments of Radiology, Weill Cornell Medical College, New York-Presbyterian Hospital, New York, New York 10065, USA. pcs9001@med.cornell.edu
authors.forename: P C
authors.initials: PC
authors.lastname: Sanelli
authors.forename: N
authors.initials: N
authors.lastname: Anumula
authors.forename: C E
authors.initials: CE
authors.lastname: Johnson
authors.forename: J P
authors.initials: JP
authors.lastname: Comunale
authors.forename: A J
authors.initials: AJ
authors.lastname: Tsiouris
authors.forename: H
authors.initials: H
authors.lastname: Riina
authors.forename: A Z
authors.initials: AZ
authors.lastname: Segal
authors.forename: P E
authors.initials: PE
authors.lastname: Stieg
authors.forename: R D
authors.initials: RD
authors.lastname: Zimmerman
authors.forename: A I
authors.initials: AI
authors.lastname: Mushlin
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002545:Brain Ischemia / Q000000981:diagnostic imaging* / Q000401:mortality*; D002544:Cerebral Infarction / Q000000981:diagnostic imaging / Q000401:mortality; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D055420:Perfusion Imaging / Q000379:methods* / Q000592:standards; D011237:Predictive Value of Tests; D011379:Prognosis; D012372:ROC Curve; D020127:Recovery of Function; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013345:Subarachnoid Hemorrhage / Q000000981:diagnostic imaging* / Q000401:mortality*; D014057:Tomography, X-Ray Computed / Q000379:methods* / Q000592:standards