title: Accuracy of computed tomography perfusion in detecting delayed cerebral ischemia following aneurysmal subarachnoid hemorrhage: a meta-analysis.
abstract: OBJECTIVE
  In recent years, significant literature shows that computed tomography perfusion (CTP) can provide sufficient information on cerebral hemodynamics and effectively indicate delayed cerebral ischemia (DCI) before the development of infarction. We aimed at performing a meta-analysis to provide a more full and accurate evaluation of CTP and CTP parameters in detecting DCI in patients with aneurysmal subarachnoid hemorrhage.
  
  
  METHODS
  We searched the PubMed, MedLine, Embase and Cochrane databases for analysis published from February 2005 to February 2013. We extracted CTP parameters, including cerebral blood volume (CBV), cerebral blood flow (CBF), mean transit time (MTT), time to peak (TTP), interhemispheric ratios for CBV and CBF and interhemispheric differences for MTT and TTP. Pooled estimates of sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR) and the summary receiver-operating characteristic curve were determined.
  
  
  RESULTS
  Four research studies are met the inclusion criteria for the analysis. The pooled sensitivity, specificity, PLR, NLR and DOR of CTP for detecting the DCI were 82%, 82%, 4.56, 0.22 and 20.96, respectively. Through the evaluation of absolute CTP parameters, CBF and MTT showed diagnostic value for DCI, but CBF and TTP did not. Moreover, CBF ratio, MTT difference and TTP difference showed more diagnostic value than CBV ratio in DCI detection by the assessment of relative CTP parameters.
  
  
  CONCLUSIONS
  As a non-invasive and short time consuming screening method, CTP own a high diagnostic value for the detection of DCI after aneurysm rupture.
authors.affiliation: Department of Neurosurgery, West China Hospital, Sichuan University, Chengdu, China.
authors.forename: Haogeng
authors.initials: H
authors.lastname: Sun
authors.forename: Hanmei
authors.initials: H
authors.lastname: Zhang
authors.forename: Junpeng
authors.initials: J
authors.lastname: Ma
authors.forename: Yi
authors.initials: Y
authors.lastname: Liu
authors.forename: Kun
authors.initials: K
authors.lastname: Wang
authors.forename: Chao
authors.initials: C
authors.lastname: You
mesh_terms: D001921:Brain / Q000000981:diagnostic imaging*; D002545:Brain Ischemia / Q000000981:diagnostic imaging* / Q000209:etiology; D002560:Cerebrovascular Circulation; D006801:Humans; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D013345:Subarachnoid Hemorrhage / Q000150:complications / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed