Applications of CT Perfusion indices in estimating early core growth in ischemic stroke

  • Author / Creator
    Nomani, Ali Z
  • Computed Tomography Perfusion (CTP) is a rapidly acquired minimally invasive mean to assess brain perfusion dynamics, collaterals and infarct growth in acute ischemic stroke (AIS). It helps differentiate expected stroke evolution and speed of core growth after arterial occlusion. The goals of this research were to determine: 1) Evaluation of means to differentiate rate of core progression in AIS and usefulness of hypoperfusion index (HI), 2) Evaluation of performance of CTP HI in medium and large - vessel occlusions (MeVO and LVO respectively) in early and late time windows, to assess infarct growth in patients with AIS, and 3) Association of cerebral small vessel disease (SVD) to HI as an imaging marker of infarct growth in patients with LVO AIS. We have shown that: 1) Estimation of progressors by definition inclusive of M2 occlusions and HI seem to be more comprehensive and can estimate rate of infarct growth with good sensitivity and specificity. External validity of these methods however requires further study. 2) HI is able to estimate the initial rate of core progression in acute ischemic stroke in patients with both MeVO and LVO comparably up to 24 hours of onset, likewise in early and late windows. Patients with HI > 0.5 have a fast rate of infarct progression that is on average ten times that of slow progressors. Further evaluation of HI however is needed to determine whether it could aid in the selection, triage and management of stroke patients treated with reperfusion therapy. 3) Advanced SVD is associated with higher HI, thus higher chances of early infarct growth in patients with LVO AIS. This can potentially support the hypothesis that increased burden of SVD is an imaging biomarker for impaired circulatory reserve and infarct growth. Future studies should explore how HI relates to SVD and can better predict micro-circulatory failure. In summary, this research has shown the utilization of hypoperfusion index as a promising tool that can help better triage and select patients with AIS for reperfusion therapy and understand the mechanisms contributing to differential infarct growth in patients with AIS.

  • Subjects / Keywords
  • Graduation date
    Fall 2021
  • Type of Item
  • Degree
    Master of Science
  • DOI
  • License
    This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.