Flat panel imaging of occlusion site and collateral scores for emergent large vessel occlusion

Published:April 10, 2019DOI:https://doi.org/10.1016/j.jns.2019.04.013


      • FPD imaging may provide an alternative workflow for acute ischemic stroke patients.
      • FPD-CTA can evaluate the site of intracranial occlusion and collateral status.
      • We found strong concordance between FPD-CTA and standard CTA on both.
      • This technique has important implications for triaging patients evaluated for MT.
      • Patients with known ELVO transferred from outside hospitals may especially benefit.



      Flat panel imaging for emergent large vessel occlusion can be acquired prior to mechanical thrombectomy (MT). In this study, we examined patients undergoing MT with computed tomography angiography (CTA) to determine agreement on the site of occlusion and CTA collateral score (CS).


      Flat Panel CTA (FP-CTA) was acquired before MT. Time between CTA and FP-CTA acquisition, site of occlusion, and CS were reported. Significant CS change was defined as >2-point change, or any change to/from a malignant profile (CS = 0 to CS > 0, or vice versa).


      Eleven patients (mean age, 60.8 years; NIHSS, 17; 55.0% female) were included; IV tPA was administered to 7. Intra-reader occlusion site, dichotomous CS, and continuous CS correlation between CTA and FP-CTA were 96.6%, 90.0%, and 86.6%, respectively. Inter-reader correlation for occlusion site was 93% for CTA and 100% for FP-CTA; dichotomous CS correlation was 87% for both CTA and FP-CTA; correlation of continuous CS was 77% for CTA and 87% for FP-CTA.


      Standard CTA and FP-CTA have high intra and inter-reader correlation determining site of occlusion and CS in ELVO setting. This angiographic tool may have potential applications for both triage and patient selection.



      CBV (cerebral blood volume), CS (collateral score), CT (computed tomography), CTA (computed tomography angiography), CTP (computed tomography perfusion), DWI (diffusion-weighted imaging), ELVO (emergent large vessel occlusion), FP-CTA (Flat Panel CTA), FPD (flat panel detectors), IV (Intravenous), MRI (magnetic resonance imaging), MSU (mobile stroke unit), MT (mechanical thrombectomy), tPA (tissue plasminogen activator)
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