破裂与非破裂颈动脉粥样硬化斑块周围血流动力学的MRl分析

Role of hemodynamic change in carotid atherosclerotic plaque rupture using MRI andcomputational fluid dynamics

目的分析颈内动脉起始部粥样硬化斑块周围血流动力学改变，探讨可能导致纤维帽破裂的流体力学因素。方法前瞻性纳入19例颈内动脉起始部粥样硬化病变患者，进行颈动脉MRI。观察斑块形态结构，并据此将斑块分为纤维帽完整组和纤维帽破裂组。利用颈动脉MR增强血管成像原始图像进行血流动力学分析，计算颈动脉分叉部血管管壁切应力（WSS）、静态压、血管狭窄率等数据，两组之间比较采用两独立样本的Mann．Whitney U检验和t检验。结果19例颈内动脉起始部斑块中，纤维帽完整组8例、斑块纤维帽破裂11例。纤维帽完整组最大管壁切应力、平均管壁切应力、最小静态压及平均静态压对应的中位数（上下四分位数范围）分别为42．92（27．13-68．19）、32．04（21．21。55．68）、-1717．36（-3433．61～-721．10）、-1341．64（-2868．00～-612．86）Pa，纤维帽破裂组对应的数据分别为67．18（60．46—139．51）、55．76（40．41～124．57）、-3884．02（-18767．39--2886．33）、-3065．92（-16064．18～-1915．09）Pa，两组间差异有统计学意义（u值分别为18．00、18．00、17．00、18．00，P值均〈0．05）。斑块纤维帽完整组和纤维帽破裂组颈内动脉狭窄率分别为（47．13±13．50）％、（62．91±11．96）％，两组之间比较差异有统计学意义（f=2．69，P=0．02）。结论破裂与非破裂颈动脉粥样硬化斑块问的血流动力学存在差异，可能会对斑块破裂造成影响。

Objective To assess the role of hemodynanfic change in the carotid atherosclerotic plaque rupture. Methods Nineteen patients with carotid atherosclerotie plaque were recruited in this study. All the plaques were divided into two groups, the intact plaques and the ruptured plaques using carotid MRI. Wall shear stress and static pressure near the plaques obtained by computational fluid dynamics were compared between two groups by using Mann-Whitney U test. Results Nineteen plaques in the internal carotid arteries were obtained, including 8 intact plaques and 11 ruptured plaques. The median （interquartile range） of maximal wall shear stress, mean wall shear stress, minimal static pressure and mean static pressure in the intact plaques were 42.92 （27.13 to 68.19）, 32.04（21.21 to 55.68）, - 1 717.36（- 3 433.61 to - 721.10）, - 1 341.64（- 2 868.00 to - 612.86） Pa, respectively. The median （interquartile range） of maximal wall shear stress, mean wall shear stress, minimal static pressure and mean static pressure in the ruptured plaques were 67.18（60.46 to 139.51）, 55.76（40.41 to 124.57）, - 3 884.02（- 18767.39to -2886.33）, - 3 065.92 （- 16 064.18 to - 1 915.09） Pa, respectively. There were significant differences in the four parameters between the two groups （U=18.00, 18.00, 17.00, 18.00;P〈0.05）. Conclusion The hemodynamics between ruptured and intact plaques is different, which may have influence on carotid atherosclerotic plaque rupture.