基于结构形态特征和力学因素的颈动脉粥样硬化危险分层定量研究

Atherosclerotic plaques often rupture without warning causing acute cerebrovascular syndromes. Atherosclerotic plaque is a multi-component structure composing of lipid-rich necrotic core, haemorrhage, calcium and fibrous cap. Increasing evidence has shown that its vulnerability has a close relationship with morphological features and component type. Apart from these, the mechanical factors cannot been overseen as plaque undertakes loading due to blood pressure and flow and the rupture possibly occurs when such loading exceeds its material strength. In this study, a risk stratification scheme for assessing carotid atherosclerotic plaque vulnerability by using the combination of magnetic resonance image (MRI)-depicted compositional features and critical mechanical conditions is proposed. A segmentation tool will be developed to identify plaque morphology and components automatically based on high resolution multi contrast MRI. The high risk structure features, including presence of haemorrhage and fibrous cap condition, will be identified. Moreover, mechanical loading will be repredicted based on the segmented results. The obtained high risk morphological and compositional features and critical mechanical conditions will be pooled to investigate their associations with subsequent symptom during the follow-up period and the risk stratification scheme will be, therefore, proposed to evaluate the plaque vulnerability. This study brings medical imaging, image processing, clinical management and biomechanical analysis under one roof from two collaborative groups. The success of this study will provide an efficient tool and pave the way to a multicentre clinical trial.

颈动脉粥样硬化斑块常因无预警性的破裂导致急性血管事件。粥样斑块是一个多组分结构, 往往含有富含脂质坏死核、血肿、钙和纤维帽等。通过对破裂斑块进行病理分析发现，脂质坏死核的大小，是否出现血肿以及纤维帽的厚度和完整性与斑块的稳定性直接相关。此外，斑块所承受的力学载荷影响也无法忽略。在生理条件下，由于血压及血流的共同作用，斑块承受着机械载荷，当这些载荷超过其自身材料强度时，斑块极可能破裂。本课题将结合结构形态特征和力学因素来研究颈动脉粥样硬化危险分层定量方法。在高分辨率多对比MR图像与统计分析的基础上，实现粥样斑块多组织成分的自动提取，得到斑块各组分的形态结构特征，同时利用生物力学来分析斑块在体状态下所受的力学载荷，分析和比较有症状患者和无症状患者的斑块成分在形态和力学特征上的差异，建立斑块病理结构与风险参数的映射模型，为区分易损斑块和稳定斑块提供客观评估依据，以细分病人组别，预测继发性病变。

颈动脉粥样硬化斑块常因无预警性的破裂导致急性血管事件。粥样斑块是一个多组分结构, 往往含有富含脂质坏死核、血肿、钙和纤维帽等。通过对破裂斑块进行病理分析发现，脂质坏死核的大小，是否出现血肿以及纤维帽的厚度和完整性与斑块的稳定性直接相关。此外，斑块所承受的力学载荷影响也无法忽略。在生理条件下，由于血压及血流的共同作用，斑块承受着机械载荷，当这些载荷超过其自身材料强度时，斑块极可能破裂。本项目结合结构形态特征和力学因素来研究颈动脉粥样硬化危险分层定量方法，具体内容包括：在高分辨率多对比MR图像与统计分析的基础上，实现了粥样斑块多组织成分的自动提取，得到了斑块各组分的形态结构特征，同时利用生物力学分析了斑块在体状态下所受的力学载荷，分析和比较了有症状患者和无症状患者的斑块成分在形态和力学特征上的差异，建立了斑块病理结构与风险参数的映射模型。项目按照计划展开了深入的理论研究，设计了相关的实验方案，进行了大量的实验测试，得出了较多的研究成果。在几个研究问题上都有较重要的科学创新，发表了约10篇论文，申请了约12项发明专利，另外本项目初期和预研阶段申请的2项发明专利获得了授权。