Abstract: Objective To evaluate the association of homocysteine(Hcy) levels with vulnerability characteristics and burden in symptomatic intracranial plaques using high-resolution vessel wall imaging (HR-VWI). 
Methods We selected 118 patients who underwent HR-VWI of the brain due to symptoms of cerebral ischemia. They were divided into high Hcy (HHcy) group (Hcy＞15 μmol/L) and normal Hcy (NHcy) group (Hcy≤15 μmol/L) based on serum pathophysiological levels of Hcy. The area, degree of stenosis, remodeling rate, and normalized wall index of symptomatic intracranial plaques were obtained, as well as the presence of vulnerability characteristics within the plaques, including contrast enhancement, intraplaque hemorrhage (IPH), and surface irregularity or positive remodeling. The vulnerability burden was graded according to the number of vulnerable characteristics in each plaque. Logistic regression model and Spearman correlation analysis were used to evaluate the relationship between Hcy level and plaque vulnerability characteristics and burden. 
Results After adjusting for demographics, vascular risk factors, and plaque measurement indicators, high Hcy level was an independent predictor of symptomatic intracranial plaque IPH ［adjusted odds ratio （OR）=3.051, 95%CI: 1.065-8.738, P=0.038］ and surface irregularity (adjusted OR=2.745, 95%CI: 1.024-7.363, P=0.045). Serum Hcy concentration was positively correlated with vulnerability burden of symptomatic plaques (r=0.524, P＜0.001). 
Conclusion Elevated Hcy levels are independently associated with IPH and surface irregularity in intracranial plaques in ischemic patients, which may play a role in vulnerability burden of intracranial plaques. 

Key words: intracranial arteriosclerosis, homocysteine, magnetic resonance imaging