Abstract: Objective  To assess the value of 320-slice computed tomography angiography (CTA) in distinguishing hemorrhage/thrombus from lipid-rich necrotic core (LRNC) in atherosclerotic plaques of carotid artery.  Methods  Thirty-seven subjects who prepared to perform carotid endarterectomy (CEA), with stenosis rate about 50%-99% in at least unilateral carotid artery detected by ultrasound, were enrolled in this study. Both 320-slice CTA and 3.0T high-resolution MRI were conducted within one week before operation. CTA, MRI and pathological sections were matched with the carotid bifurcation and calcification features as the mark. According to American Heart Association (AHA) modified classification, CT slices were selected and divided into 2 groups: Type Ⅳ -Ⅴ (lipid plaques) and Type Ⅵ (hemorrhage plaques), and the density difference between lipid plaques and hemorrhage/thrombus plaques was analyzed.  Results  A total of 217 slices were included in final analysis, including 88 slices of Type Ⅳ -Ⅴ (lipid plaques) and 129 slices of Type Ⅵ (hemorrhage plaques). There was statistically significant difference in CT value between 2 groups. The mean CT value of lipid necrosis core in Type Ⅳ -Ⅴ and hemorrhage/thrombus in Type Ⅵ was (28.07 ± 26.84) and (97.17 ± 35.82) HU respectively, and the former wassignificantly lower than the latter (t = 16.141, P = 0.000).  Conclusions  CTA can distinguish hemorrhage/thrombus from lipid-rich necrotic core in carotid atherosclerotic plaques.

Key words: Atherosclerosis, Carotid stenosis, Endarterectomy, carotid, Tomography, X-ray computed, Angiography

摘要： 目的 评价320 层容积CTA 对颈动脉粥样硬化斑块富脂坏死核心和出血/血栓形成部分的分辨价值。方法 选择2010 年4 月-2011 年12 月单侧颈动脉狭窄（50% ~ 99%）并拟行颈动脉内膜切除术患者共37 例。分别于术前1 周行320 层容积CTA 和高分辨力MRI检查， 结合多对比MRI信号特点，按照美国心脏协会分型标准分为Ⅳ ~ Ⅴ型斑块（脂质斑块）组和Ⅵ型斑块（出血斑块）组；比较脂质斑块与出血斑块CT 值差异。结果 最终共纳入31 例共217 层扫描层面，脂质斑块88 层、出血斑块129 层。脂质斑块组脂质核和出血斑块组出血/血栓形成部分的平均CT 值分别为（28.07 ± 26.84）和（97.17 ± 35.82）HU，两组差异有统计学意义（t = 16.141，P = 0.000）。结论 测量颈动脉粥样硬化斑块CT 值可以帮助区分斑块内成分，识别出血斑块，有助于判断斑块之易损性。

关键词: 动脉粥样硬化, 颈动脉狭窄, 颈动脉内膜切除术, 体层摄影术, X 线计算机, 血管造影术