HRMRI characteristics and clinical risk factors of intracranial atherosclerotic plaques in patients with ischemic stroke

Purpose: To characterize the intracranial atherosclerotic plaques in patients with ischemic stroke and investigate the risk factors of vulnerable plaques by using 3.0 T high resolution MRI. Methods: Forty nine patients (35 male, 14 female, age 31-81 years, mean age 60.73 ± 12.4 years) with ischemic stroke underwent 3.0 T high resolution MRI. All plaques were categorized into 2 groups (culprit artery plaques and nonculprit artery plaques) according to the vascular territory of the stroke, and the characteristics of the plaques were investigated between the 2 groups. The plaques were also categorized into 2 groups (obvious enhancement/mild or none enhancement) according to the strength of plaque enhancement, then the clinical and laboratory characteristics were compared between the two groups, and the risk factors for vulnerable plaque were investigated. The chi-square test was used to compare the categorical variables, and the independent t-test was used to compare the continuous variables. Results: Total 196 plaques were identified in 49 patients, seventy (35.7%) were culprit artery plaques, one hundred twenty seven (64.3%) were nonculprit artery plaques. There were significant differences between the 2 groups in the degree of luminal stenosis and the proportion of plaques obviously enhanced (P < 0.001). The degree of luminal stenosis and plaque enhancement were significantly higher in the culprit artery plaque group than in the nonculprit artery plaque group (P < 0.001). There was no significant difference in age, gender, hypertension, diabetes mellitus, smoking, past stroke history, and family history between the obvious enhancement group and the mild or none enhancement group. The LDL/HDL ratio was significantly lower in the mild or none enhancement group than obvious enhancement group (1.95 ± 0.62 and 2.53 ± 0.94, respectively, P = 0.048). Conclusions: Obvious enhancement of intracranial artery plaque may associate with ischemic stroke. The degree of plaque enhancement can reflect the stability of plaques.The common risk factors of intracranial atherosclerosis do not fully reflect the stability of plaques. LDL/HDL ratio may predict the vulnerability of the intracranial atherosclerotic plaques. (authors)