Purpose: The present study aimed to assess the associations of expansive remodeling of carotid arteries with ischemic symptoms and the degree of stenosis.Materials and Methods: A total of 41 symptomatic patients with vulnerable plaques and 25 asymptomatic individuals with stable plaques were included.All patients underwent 3.0T high-resolution MRI of the carotid artery (CA) for measuring the ex pansive remodeling (ER) ratio and assessing plaque stability.The ER ratio was calculated by dividing the maximum distance between the lumen and the outer border of the plaque in the inteal CA by the lumen diameter within 1 centimeter of the plaque at the distal ipsilateral inteal CA.ER ratios were compared between the symptomatic and asymptomatic groups.The 41 symp tomatic patients were further divided into 4 groups according to stenosis rate (CA stenosis ＜50％,50％-74％,75-89％,and ＞ 90％),and the correlation between the ER ratio and the rate of stenosis was evaluated.Results: There was a significant difference in ER ratio between the symptomatic and asymptomatic groups (p＜0.001).When symptomatic patients were divided into 4 subgroups based on degree of stenosis,ER ratios among groups showed statistically significant differences (p=0.014).Conclusion: There were significant associations of the ER ratio with ischemic symptoms.Furthermore,the ER ratio in symptomatic patients continued to increase with stenosis severity.These findings suggested that the ER ratio might be a practical marker of plaque vulnerability in the CA and further prospective studies for asymptomatic patients are warranted.