Time-dependent computed tomographic perfusion thresholds for patients with acute ischemic stroke

Christopher D. D'Esterre, Mari E. Boesen, Seong Hwan Ahn, Pooneh Pordeli, Mohamed Najm, Priyanka Minhas, Paniz Davari, Enrico Fainardi, Marta Rubiera, Alexander V. Khaw, Andrea Zini, Richard Frayne, Michael D. Hill, Andrew M. Demchuk, Tolulope T. Sajobi, Nils D. Forkert, Mayank Goyal, Ting Y. Lee, Bijoy K. Menon

Research output: Contribution to journalArticlepeer-review

105 Scopus citations


Background and Purpose - Among patients with acute ischemic stroke, we determine computed tomographic perfusion (CTP) thresholds associated with follow-up infarction at different stroke onset-to-CTP and CTP-to-reperfusion times. Methods - Acute ischemic stroke patients with occlusion on computed tomographic angiography were acutely imaged with CTP. Noncontrast computed tomography and magnectic resonance diffusion-weighted imaging between 24 and 48 hours were used to delineate follow-up infarction. Reperfusion was assessed on conventional angiogram or 4-hour repeat computed tomographic angiography. Tmax, cerebral blood flow, and cerebral blood volume derived from delay-insensitive CTP postprocessing were analyzed using receiver-operator characteristic curves to derive optimal thresholds for combined patient data (pooled analysis) and individual patients (patient-level analysis) based on time from stroke onset-to-CTP and CTP-to-reperfusion. One-way ANOVA and locally weighted scatterplot smoothing regression was used to test whether the derived optimal CTP thresholds were different by time. Results - One hundred and thirty-two patients were included. Tmax thresholds of >16.2 and >15.8 s and absolute cerebral blood flow thresholds of <8.9 and <7.4 mL·min-1·100 g-1 were associated with infarct if reperfused <90 min from CTP with onset <180 min. The discriminative ability of cerebral blood volume was modest. No statistically significant relationship was noted between stroke onset-to-CTP time and the optimal CTP thresholds for all parameters based on discrete or continuous time analysis (P>0.05). A statistically significant relationship existed between CTP-to-reperfusion time and the optimal thresholds for cerebral blood flow (P<0.001; r=0.59 and 0.77 for gray and white matter, respectively) and Tmax (P<0.001; r=-0.68 and -0.60 for gray and white matter, respectively) parameters. Conclusions - Optimal CTP thresholds associated with follow-up infarction depend on time from imaging to reperfusion.

Original languageEnglish (US)
Pages (from-to)3390-3397
Number of pages8
Issue number12
StatePublished - Dec 1 2015
Externally publishedYes


  • CT
  • acute ischemic stroke
  • endovascular therapy
  • infarction
  • perfusion

ASJC Scopus subject areas

  • Clinical Neurology
  • Cardiology and Cardiovascular Medicine
  • Advanced and Specialized Nursing


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