Objective: This research aims to analyze the perivascular fat density (PFD) and vulnerable features of carotid plaques in acute ischemic stroke (AIS) patients, and explore their correlations with stroke severity and prognosis via carotid computed tomography angiography (CTA) and high - resolution vessel wall MRI (HRVW - MRI).

Method: This was a retrospective analysis of 106 patients diagnosed with AIS from January 2019 to December 2022. Plaque features included PFD, intraplaque hemorrhage (IPH), plaque enhancement, plaque ulceration, calcification, maximum wall thickness and the degree of luminal stenosis. According to the National Institutes of Health Stroke Scale, the severity of stroke in patients was divided into mild (NIHSS=1-4) and moderate to severe (NIHSS > 4). According to the Modified Rankin Scale at 90 days, the prognosis of patients was divided into good (mRS=0-2) and poor (mRS>2). Multivariate logistic regression analysis were used to assess the relationship between imaging and clinical characteristics and stroke severity and prognosis.

Results: Patients in the moderate to severe stroke group had lower BMI, higher PFD, higher degree of lumen stenosis, and were more prone to IPH and plaque enhancement. PFD, plaque enhancement, and IPH were independently associated with stroke severity. Patients in the poor prognosis group had lower BMI, higher PFD, higher NIHSS scores, and were more prone to IPH and plaque enhancement. IPH was independently associated with stroke prognosis.

Conclusion: Based on HRVW - MRI and CTA, IPH, plaque enhancement and PFD are independent factors for stroke severity, and IPH may independently predict AIS prognosis.