CTP-based estimated ischemic core: A comparative multicenter study between Olea and RAPID software

V Yedavalli; S Kihira; P Shahrouki; O Hamam; E Tavakkol; M McArthur; J Qiao; Fifi Johanna; A Doshi; A Vagal; P Khatri; A Srinivasan; N Chaudhary; M Bahr-Hosseini; G P Colby; M Nour; R Jahan; G Duckwiler; C Arnold; J L Saver; J Mocco; D S Liebeskind; K Nael

doi:10.1016/j.jstrokecerebrovasdis.2023.107297

CTP-based estimated ischemic core: A comparative multicenter study between Olea and RAPID software

J Stroke Cerebrovasc Dis. 2023 Nov;32(11):107297. doi: 10.1016/j.jstrokecerebrovasdis.2023.107297. Epub 2023 Sep 20.

Authors

V Yedavalli¹, S Kihira², P Shahrouki², O Hamam³, E Tavakkol², M McArthur², J Qiao², Fifi Johanna⁴, A Doshi⁴, A Vagal⁵, P Khatri⁵, A Srinivasan⁶, N Chaudhary⁶, M Bahr-Hosseini², G P Colby², M Nour², R Jahan², G Duckwiler², C Arnold², J L Saver², J Mocco⁴, D S Liebeskind², K Nael²

Affiliations

¹ Johns Hopkins University School of Medicine, Baltimore, MD, United States. Electronic address: Vyedava1@jhmi.edu.
² David Geffen School of Medicine at the University of California - Los Angeles, United States.
³ Massachussetts General Hospital, Boston, MA, United States.
⁴ Mount Sinai School of Medicine, New York, NY, United States.
⁵ University of Cincinnati School of Medicine, Cincinnati, OH, United States.
⁶ University of Michigan School of Medicine, Ann Arbor, MI, United States.

PMID: 37738915
DOI: 10.1016/j.jstrokecerebrovasdis.2023.107297

Abstract

Background and purpose: CTP is increasingly used to assess eligibility for endovascular therapy (EVT) in patients with large vessel occlusions (LVO). There remain variability and inconsistencies between software packages for estimation of ischemic core. We aimed to use heterogenous data from four stroke centers to perform a comparative analysis for CTP-estimated ischemic core between RAPID (iSchemaView) and Olea (Olea Medical).

Methods: In this retrospective multicenter study, patients with anterior circulation LVO who underwent pretreatment CTP, successful EVT (defined TICI ≥ 2b), and follow-up MRI included. Automated CTP analysis was performed using Olea platform [rCBF < 25% and differential time-to-peak (dTTP)>5s] and RAPID (rCBF < 30%). The CTP estimated core volumes were compared against the final infarct volume (FIV) on post treatment MRI-DWI.

Results: A total of 151 patients included. The CTP-estimated ischemic core volumes (mean ± SD) were 18.7 ± 18.9 mL on Olea and 10.5 ± 17.9 mL on RAPID significantly different (p < 0.01). The correlation between CTP estimated core and MRI final infarct volume was r = 0.38, p < 0.01 for RAPID and r = 0.39, p < 0.01 for Olea. Both software platforms demonstrated a strong correlation with each other (r = 0.864, p < 0.001). Both software overestimated the ischemic core volume above 70 mL in 4 patients (2.6%).

Conclusions: Substantial variation between Olea and RAPID CTP-estimated core volumes exists, though rates of overcalling of large core were low and identical. Both showed comparable core volume correlation to MRI infarct volume.

Keywords: Acute ischemic stroke; CT perfusion; Endovascular thrombectomy; Large vessel occlusion.