Is infarct core growth linear? Infarct volume estimation by computed tomography perfusion imaging

• Published in: Acta Neurologica Scandinavica
• Main Authors: Suomalainen, Olli P., Elseoud Abou, Ahmed, Martinez-Majander, Nicolas, Tiainen, Marjaana, Valkonen, Kati, Virtanen, Pekka, Forss, Nina, Curtze, Sami
• Other Authors: University of Helsinki, Department of Neuroscience and Biomedical Engineering, Helsinki University Hospital, Aalto-yliopisto, Aalto University
• Format: Article in Journal/Newspaper
• Language: English
• Published: WILEY-BLACKWELL 2022
• Subjects: computed tomography; CT perfusion; endovascular thrombectomy; ischemic core; ischemic stroke; outcome; karelian
• Online Access: https://aaltodoc.aalto.fi/handle/123456789/119171; https://doi.org/10.1111/ane.13601

Funding Information: This project was granted funding for 2019 and 2020 by the Helsinki University Hospital governmental subsidiary funds for clinical research (Y1249NEUR1), the Maire Taponen foundation, and the South Karelian Medical Association Publisher Copyright: © 2022 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd Objectives: Current guidelines for recanalization treatment are based on the time elapsed between symptom onset and treatment and visualization of existing penumbra in computed tomography perfusion (CTP) imaging. The time window for treatment options relies on linear growth of infarction although individual infarct growth rate may vary. We aimed to test how accurately the estimated follow-up infarct volume (eFIV) can be approximated by using a linear growth model based on CTP baseline imaging. If eFIV did not fall within the margins of +/− 19% of the follow-up infarct volume (FIV) measured at 24 h from non-enhanced computed tomography images, the results would imply that the infarct growth is not linear. Materials and Methods: All consecutive endovascularly treated (EVT) patients from 11/2015 to 9/2019 at the Helsinki University Hospital with large vessel occlusion (LVO), CTP imaging, and known time of symptom onset were included. Infarct growth rate was assumed to be linear and calculated by dividing the ischemic core volume (CTPcore) by the time from symptom onset to baseline imaging. eFIV was calculated by multiplying the infarct growth rate with the time from baseline imaging to recanalization or in case of futile recanalization to follow-up imaging at 24 h, limited to the penumbra. Collateral flow was estimated by calculating hypoperfusion intensity ratio (HIR). Results: Of 5234 patients, 48 had LVO, EVT, CTP imaging, and known time of symptom onset. In 40/48 patients (87%), infarct growth was not linear. HIR did not differ between patients with linear and nonlinear growth (p >.05). As expected, in over half of the patients with successful recanalization eFIV exceeded ...