Imaging of non-stenotic carotid plaque for embolic stroke of undetermined source

Purpose: Ischemic stroke is a significant cause of death and disability. Embolic Stroke of Undetermined Source (ESUS) accounts for a large proportion of acute ischemic strokes. A clear etiology is crucial for the treatment and prevention of stroke. The pathogenic mechanism of non-stenotic carotid plaque (NSCP) in ESUS is not yet fully understood. This study used computed tomographic angiography (CTA) to assess the correlation between NSCP and ESUS. Method: Eighty-one patients with unilateral anterior circulation ESUS were retrospectively enrolled between June 2020 and June 2022. The prevalence of NSCP, degree of stenosis, plaque thickness, plaque type, plaque irregularity, plaque ulceration, focal areas of hypodensity within the plaque, and positive remodeling were evaluated in both carotid arteries on CTA. Univariate and multivariate logistic regression were used to determine the relationship between NSCP, plaque characteristics, and ipsilateral stroke. Results: Among 81 patients with unilateral anterior circulation ESUS, the incidence of NCSP was significantly higher in the ipsilateral carotid artery than in the contralateral side (76.5 % vs. 60.5 %, P = 0.028). Plaque type, plaque thickness, plaque thickness >3 mm, and focal areas of hypodensity within the plaque were remarkably different between two sides of carotid plaques (all P < 0.05). In addition, multifactorial logistic regression showed that intraplaque hypodensity (aOR = 6.449 [95 % CI, 1.818-22.878]) and greater plaque thickness (aOR = 2.476 [95 % CI, 1.14-5.38]) were significantly associated with ESUS. Conclusions: The prevalence of NSCP ipsilateral to stroke is higher in ESUS patients, and more complex plaque features were found on the ipsilateral side. Greater plaque thickness and hypodensity within the plaque were significantly associated with ESUS, and these plaques may be an important embolization source of ESUS.