多模态影像学新技术评估冠状动脉粥样硬化斑块组织学特性及预测药物干预治疗后斑块转归的可行性研究

Unstable coronary atherosclerotic plaque, which is also known as thin-cap fibroatheroma (TCFA), is the main cause of acute cardiovascular events and sudden cardiac death. The early detection and intervention to TCFA is of clinical significance to reduce the mortality and morbidity of major adverse cardiac events. The assessment of TCFA is mainly based on invasive intra-coronary imaging modalities, which are not available for general screening and diagnosis in high-risk patients. Out previous studies have revealed the imaging features of different stages of coronary plaques and thrombus by CTA without pathology correlation. Therefore, the main aim of this study is to identify the spectral CT and MR plaque imaging features of TCFA in the porcine model of coronary atherosclerosis, with reference to histopathology correlation. We will consequently be able to establish the diagnostic criteria of non-invasive imaging of TCFA in order to facilitate the early detection and treatment of unstable coronary plaques..In addition, we also aim to reveal the non-invasive imaging features of coronary atherosclerotic plaques for prediction their treatment response to medical intervention by follow-up of patients with spectral CT imaging prior to and after statin treatment. Therefore, we will be able to propose a novel plaque classification based on their imaging features on spectral CT and subsequently guide individualized treatment.

不稳定冠状动脉粥样硬化斑块、即TCFA，是导致急性心血管事件发生和患者心源性猝死的主要原因之一，其早期检出和干预对减少心脏不良事件的发生率具有重要意义。目前TCFA的影像学评价以有创性冠状动脉腔内成像为主，无法常规用于高危患者的诊断和筛查。本团队的前期研究使用常规CTA成像发现了不同时期冠状动脉斑块及血栓的影像学特征。在此基础上，本项目拟通过猪冠状动脉粥样硬化斑块模型的多模态影像学评估，明确不同类型冠状动脉粥样硬化斑块各自相对应的能谱CT和磁共振T1WI成像参数特征，建立无创性影像学评价不稳定冠状动脉粥样硬化斑块的体系和标准，为临床高危患者中不稳定冠状动脉粥样硬化斑块的早期诊断和治疗提供基础。同时，通过冠状动脉粥样硬化患者他汀类药物治疗前后能谱CT随访复查的对比，得到可预测斑块对降脂治疗反应的能谱成像参数特性，建立基于冠状动脉斑块能谱CT参数特征的斑块分型，进而指导制订个体化治疗方案。

不稳定冠状动脉粥样硬化斑块是导致急性心血管事件发生和患者心源性猝死的主要原因之一，其早期检出和干预对减少心脏不良事件的发生率具有重要意义。目前不稳定斑块的影像学评价以有创性冠状动脉腔内成像为主，无法常规用于高危患者的诊断和筛查。本课题通过对猪冠状动脉粥样硬化斑块模型和冠状动脉粥样硬化患者的多模态影像学评估，明确了低密度斑块成分是与不稳定斑块相关的最佳无创性影像学参数指标，初步建立无创性影像学评价不稳定冠状动脉粥样硬化斑块的体系和标准，为临床中-高危患者中不稳定冠状动脉粥样硬化斑块的早期诊断和治疗提供基础。同时，通过冠状动脉粥样硬化患者他汀类药物治疗前后能谱CT随访复查的对比，明确了非钙化斑块及混合型斑块对于他汀药物治疗效果最佳，斑块周围脂肪密度指数以及斑块CT-FFR可反应他汀治疗后不稳定斑块炎症反应的吸收和病变血流动力学的改善，建立基于冠状动脉斑块CT参数特征的斑块分型，进而指导制订个体化治疗方案。此外，课题组还通过与压力导丝FFR的对照，证实了CT心肌灌注成像定量获得的心肌血流量（MBF）参数对于诊断缺血性病变具有最佳的诊断准确性。斑块周围脂肪密度指数与斑块体积及直径狭窄相结合，可显著提高CTA对于血流动力学阳性病变的检出准确率，为指导粥样硬化斑块的治疗策略选择提供了基于无创性影像学的循证学依据。