Abstract Number: LBA8 Thin Cut Non‐Contrast Computed Tomography for Periprocedural Planning: Thrombus Burden Assessment Prior to Mechanical Thrombectomy

Abstract

Introduction In patients presenting with acute ischemic stroke (AIS), non‐contrast CT (NCCT) and CT angiography (CTA) are used to determine large vessel occlusions (LVO). Using thin‐cut NCCT, hyperdense signs represent thrombus. NCCT provides information on thrombus characteristics such as length and morphology that is not evidenced by CTA. The aim of this study is to determine if hyperdense signs identified on thin‐cut NCCT are a valid tool in periprocedural planning for endovascular thrombectomy (EVT). Methods At our comprehensive stroke center, patients presenting with AIS who had thin‐cut NCCT defined as 0.625mm per slice followed by EVT and subsequent High Resolution Photographs (HRPs) of post‐EVT thrombus were identified. High‐resolution photographs were taken by operating physician with adjacent ruler for accurate measurement. Thin‐cut NCCT and associated fully extracted thrombus HRPs were reviewed by two board certified vascular neurologists to determine agreement. Cohen’s K was used to determine kappa inter‐rater agreement. Wilcoxon signed‐rank test was used to determine if significant difference existed between thrombus length and independently measured hyperdense sign. Social science statistics software was used for data analysis. Results From January 2019 to December 2021, out of 87 cases where thrombus was extracted after EVT, 57 met inclusion criteria and had associated initial CT head. Mean age was 68.22 (95% CI 64.26, 72.18), and 49% were female (n = 28). Mean thrombus length was 12.49mm (95% CI 10.19, 14.80). Mean hyperdense sign length measured by Interpreter 1 was 12.86mm (95% CI 10.54, 15.18). Mean hyperdense sign length measured by Interpreter 2 was 12.61mm (95% CI 10.40, 14.83). Kappa score was 1. There was no significant difference in thrombus length and Interpreter 1 hyperdense sign (z = 0.99; p‐value 0.317) or Interpreter 2 hyperdense sign (z = ‐0.92; p‐value = 0.36). Conclusions Our study suggests that in acute ischemic stroke patients, hyperdense sign on thin‐cut NCCT may be a valid reliable marker of thrombus length and morphology that assists in peri‐procedural planning for mechanical thrombectomy. Larger, prospective studies are needed to validate our results.