title: Prolonged Cerebral Circulation Time Is the Best Parameter for Predicting Vasospasm during Initial CT Perfusion in Subarachnoid Hemorrhagic Patients.
abstract: OBJECTIVE
  We sought to imitate angiographic cerebral circulation time (CCT) and create a similar index from baseline CT perfusion (CTP) to better predict vasospasm in patients with subarachnoid hemorrhage (SAH).
  
  
  METHODS
  Forty-one SAH patients with available DSA and CTP were retrospectively included. The vasospasm group was comprised of patients with deterioration in conscious functioning and newly developed luminal narrowing; remaining cases were classified as the control group. The angiography CCT (XA-CCT) was defined as the difference in TTP (time to peak) between the selected arterial ROIs and the superior sagittal sinus (SSS). Four arterial ROIs were selected to generate four corresponding XA-CCTs: the right and left anterior cerebral arteries (XA-CCTRA2 and XA-CCTLA2) and right- and left-middle cerebral arteries (XA-CCTRM2 and XA-CCTLM2). The CCTs from CTP (CT-CCT) were defined as the differences in TTP from the corresponding arterial ROIs and the SSS. Correlations of the different CCTs were calculated and diagnostic accuracy in predicting vasospasm was evaluated.
  
  
  RESULTS
  Intra-class correlations ranged from 0.96 to 0.98. The correlations of XA-CCTRA2, XA-CCTRM2, XA-CCTLA2, and XA-CCTLM2 with the corresponding CT-CCTs were 0.64, 0.65, 0.53, and 0.68, respectively. All CCTs were significantly prolonged in the vasospasm group (5.8-6.4 s) except for XA-CCTLA2. CT-CCTA2 of 5.62 was the optimal cut-off value for detecting vasospasm with a sensitivity of 84.2% and specificity 82.4.
  
  
  CONCLUSIONS
  CT-CCTs can be used to interpret cerebral flow without deconvolution algorithms, and outperform both MTT and TTP in predicting vasospasm risk. This finding may help facilitate management of patients with SAH.
authors.affiliation: Department of Neurosurgery, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan.|School of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Chun Fu
authors.initials: CF
authors.lastname: Lin
authors.affiliation: Department of Neurosurgery, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan.|School of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Sanford P C
authors.initials: SP
authors.lastname: Hsu
authors.affiliation: Department of Radiology, Taipei Veterans General Hospital, Taipei, Taiwan.|School of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Chung Jung
authors.initials: CJ
authors.lastname: Lin
authors.affiliation: Department of Radiology, Taipei Veterans General Hospital, Taipei, Taiwan.|School of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Wan Yuo
authors.initials: WY
authors.lastname: Guo
authors.affiliation: Department of Neurosurgery, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan.|School of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Chih Hsiang
authors.initials: CH
authors.lastname: Liao
authors.affiliation: Department of Radiology, Taipei Veterans General Hospital, Taipei, Taiwan.|School of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Wei Fa
authors.initials: WF
authors.lastname: Chu
authors.affiliation: Department of Radiology, Taipei Veterans General Hospital, Taipei, Taiwan.|School of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Sheng Che
authors.initials: SC
authors.lastname: Hung
authors.affiliation: Department of Neurosurgery, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan.|School of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Yang Shin
authors.initials: YS
authors.lastname: Shih
authors.affiliation: Department of Radiology, Taipei Veterans General Hospital, Taipei, Taiwan.|School of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Yen Tzu
authors.initials: YT
authors.lastname: Lin
mesh_terms: D015901:Angiography, Digital Subtraction / Q000379:methods; D002560:Cerebrovascular Circulation / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D055420:Perfusion Imaging / Q000379:methods; D013345:Subarachnoid Hemorrhage / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology*; D014057:Tomography, X-Ray Computed / Q000379:methods; D020301:Vasospasm, Intracranial / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology*