Abstract DP313: Characterizing PlaqueRADS Across Stroke Etiologies: A CTA and Vessel Wall Imaging Study in Unilateral Anterior Circulation Stroke.

Background and Aims: High-risk carotid plaque features may contribute to atherosclerotic ischemic stroke beyond stenosis severity. PlaqueRADS is a multimodal grading system integrating plaque vulnerability markers, but its patterns using CTA plus vessel wall imaging (VWI) across stroke etiologies remain unclear. We aimed to compare PlaqueRADS distributions across etiologic subtypes and explore whether ipsilateral scoring provides insights into ESUS mechanisms. Methods: We retrospectively studied patients with unilateral anterior circulation ischemic stroke at a single center who underwent CTA+VWI and met diagnostic criteria for cardioembolic (CE) or large-artery atherosclerotic (LAA) per TOAST, and ESUS per 2022 criteria excluding high-risk PFO. PlaqueRADS was independently scored by three radiologists, excluding cases without bilaterally evaluable arteries. Between-group comparisons were performed using Wilcoxon rank-sum tests, and ipsilateral–contralateral paired analyses with Wilcoxon signed-rank and Sign tests at different PlaqueRADS thresholds. Results: Among 163 patients (CE=71, LAA=48, ESUS=44), ipsilateral PlaqueRADS ≥3 was more frequent in LAA (64.6%) and CE (45.07%) than in ESUS (27.3%). Ipsilateral scores were higher in LAA vs CE (p