颈动脉粥样硬化斑块内出血多层CT血管成像研究

Assessment of 320-slice computed tomography angiography in distinguishing hemorrhage in carotid atherosclerotic plaques

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。

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 uhrasound, 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 was significantly lower than the latter （t = 16.141, P = 0.000）. Conclusions CTA can distinguish hemorrhage/ thrombus from lipid-rich necrotic core in carotid atherosclerotie plaques.