磁共振成像对症状性颈动脉狭窄和粥样硬化斑块特征的诊断价值

Value of Magnetic Resonance Imaging in the Diagnosis of Symptomatic Carotid Stenosis and Atherosclerotic Plaque Characteristics

目的探讨磁共振成像(MRI)对症状性颈动脉狭窄与粥样硬化斑块特征的诊断价值。方法回顾性分析50例症状性颅外段颈动脉粥样硬化性狭窄患者的MRI及数字减影血管造影(DSA)结果。以NASCET标准确定狭窄率和狭窄程度。以DSA为"金标准",检验MRI对颈动脉不同狭窄程度检测的敏感性、特异性、准确性及与DSA检测结果的一致性。计算颈动脉不同狭窄程度中斑块内出血、破裂纤维帽的比率。结果以DSA检测结果为"金标准",MRI检测的敏感性、特异性、准确性如下:轻度狭窄为93.1%、97.5%、90.6%,中度狭窄为84.2%、94.9%、79.1%,重度狭窄为100%、97.5%、97.5%,完全闭塞为100%、100%、100%。MRI和DSA的一致性系数Kappa值为0.863。轻度狭窄、中度狭窄、重度狭窄斑块内出血的比率分别为29.1%、45.0%、52.6%,破裂纤维帽的比率分别为23.6%、40.0%、57.9%。结论 MRI对颈动脉粥样硬化病变有很高的诊断价值.不但能评价颈动脉狭窄程度,而且根据信号特点能分析斑块组成成分,有助于脑血管疾病的早期诊断及早期治疗。

Aim To investigate the value of magnetic resonance imaging （MRI） in the diagnosis of symptomatic carotid stenosis and atherosclerotic plaque characteristics. Methods A total of fifty patients with symptomatic carotid stenosis which was determined by digital subtraction angiography （DSA） underwent bilateral carotid MRI examination. Stenosis percentage and stenosis degree were confirmed by using North American Symptomatic Carotid Endarterectomy Trial （NASCET） standard. With DSA as the ＂gold standard＂ , the results of MRI and DSA were compared to evaluate the sen- sitivity, specificity and accuracy of MRI in the diagnosis of different degree of carotid stenosis. The incidence rates of in- traplaque hemorrhage （IPH） and rupture fibrous cap （RFC） were calculated in different degrees of carotid stenosis. Results With DSA results as the ＂gold standard＂ , the sensitivity, specificity and accuracy of MRI detection were as fol- lows： 93.1%, 97. 5% and 90. 6% in mild stenosis, 84. 2%, 94. 9% and 79. 1% in moderate stenosis, 100%, 97.5% and 97.5% in severe stenosis, 100%, 100% and 100% in occlusion. The consistency coefficient of MRI and DSA i. e. Kappa value was 0. 863. The rates of IPH were 29. 1% , 45.0% and 52. 6% and the rates of RFC were 23.6% , 40.0% and 57. 9% respectively in mild stenosis, moderate stenosis and severe stenosis. Conclusions MRI has a high diagnostic value for carotid atherosclerosis and is helpful for early diagnosis and early treatment of cerebrovascular disease. It can not only evaluate the degree of carotid stenosis, but also analyze the composition of plaque according to the signal characteristics.