缺血性卒中病人颅内动脉硬化斑块的HRMRI特征及相关临床危险因素研究

目的利用3.0 T高分辨力MR成像(HRMRI)技术分析缺血性卒中病人颅内责任动脉斑块特征,并探讨颅内动脉不稳定斑块的临床相关危险因素。方法共纳入49例缺血性脑卒中病人行颅内动脉HRMRI检查,男35例,女14例,年龄31~81岁,平均年龄(60.73±12.4)岁。根据病人斑块与缺血区责任动脉的关系分为责任动脉斑块组和非责任动脉斑块组,分析2组病人的HRMRI特征。根据斑块的强化程度分为明显强化组和非明显强化组,分析斑块强化程度与临床相关危险因素的关系。计数资料采用χ2检验,计量资料采用t检验进行统计学分析。结果 49例病人共196处斑块,其中责任动脉斑块70处(35.7%),非责任动脉斑块126处(64.3%);2组间的管腔狭窄程度、斑块明显强化的比例等差异有统计学意义(P0.001),责任动脉斑块所致的管腔狭窄程度更为严重、明显强化的比例更高(P0.001)。明显强化组与非明显强化组之间的年龄、性别、高血压、糖尿病、吸烟史、既往卒中史及家族史差异均无统计学意义。非明显强化组的低密度脂蛋白/高密度脂蛋白(LDL/HDL)比值低于明显强化组(分别为1.95±0.62和2.53±0.94,P=0.048)。结论颅内动脉粥样硬化斑块的强化与缺血性卒中事件的发生密切相关。斑块的强化程度能够反映斑块的稳定性。颅内动脉粥样硬化常见的危险因素并不能完全反映斑块的稳定性,LDL/HDL比值升高有可能作为不稳定斑块的预测因子。

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 plaquemay 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.