Carotid plaque neovascularization is one of the major factors for the classification of vulnerable plaque, but the axial force effects of the pulsatile blood flow on the plaque with neovessel and intraplaque hemorrhage was unclear. Together with the severity of stenosis, the fibrous cap thickness, large lipid core, and the neovascularization followed by intraplaque hemorrhage (IPH) have been regarded as high-risk features of plaque rupture. In this work, the effects of these factors were evaluated on the progression and rupture of the carotid atherosclerotic plaques. Five geometries of carotid artery plaque were developed based on contrast-enhanced ultrasound (CEUS) images, which contain two types of neovessel and IPH, and geometry without neovessel and IPH. A one-way fluid-structure interaction model was applied to compute the maximum principal stress and strain in the plaque. For that hyper-elastic and non-linear material, Yeoh 3rd Order strain energy density function was used for components of the plaque. The simulation results indicated that the maximum principal stress of plaque in the carotid artery was higher when the degree of the luminal stenosis increased and the thickness of the fibrous cap decreased. The neovessels within the plaque could introduce a 2.5% increments of deformation in the plaque under the pulsatile blood flow pressure. The IPH also contributed to the increased risk of plaque rupture that a gain of stress was 8.983, 14.526, and 34.47 kPa for the plaque with 50, 65, and 75%, respectively, when comparing stress in the plaque with IPH distributed at the middle to the shoulder of the plaque. In conclusion, neovascularization in the plaque could reduce the stability of the plaque by increasing the stress within the plaque. Also, the risk of plaque rupture increased when large luminal stenosis, thin fibrous cap, and IPH were observed.

中文翻译：

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基于 CEUS 图像，通过计算斑块中的应力/应变来研究人类颈动脉粥样硬化斑块破裂的因素：数值研究

颈动脉斑块新生血管形成是易损斑块分类的主要因素之一，但脉动血流对新血管和斑块内出血斑块轴向力的影响尚不清楚。连同狭窄的严重程度，纤维帽的厚度、大的脂质核心以及随后的斑块内出血（IPH）的新生血管形成被认为是斑块破裂的高风险特征。在这项工作中，评估了这些因素对颈动脉粥样硬化斑块进展和破裂的影响。基于对比增强超声 (CEUS) 图像开发了五种几何形状的颈动脉斑块，其中包含两种类型的新血管和 IPH，以及没有新血管和 IPH 的几何形状。应用单向流固耦合模型来计算斑块中的最大主应力和应变。对于这种超弹性和非线性材料，Yeoh 三阶应变能量密度函数用于斑块的组成部分。模拟结果表明，随着管腔狭窄程度的增加和纤维帽厚度的减小，颈动脉斑块的最大主应力较高。在脉动血流压力下，斑块内的新血管可在斑块中引入 2.5% 的变形增量。IPH 还导致斑块破裂风险增加，斑块应力增加分别为 8.983、14.526 和 34.47 kPa，分别为 50、65 和 75%，当将斑块中的应力与分布在斑块肩部中间的 IPH 进行比较时。总之，斑块中的新生血管化可以通过增加斑块内的应力来降低斑块的稳定性。此外，当观察到大管腔狭窄、薄纤维帽和 IPH 时，斑块破裂的风险增加。