Evaluation of Regional Arterial Wall Elasticity and Intra-atheromatous Physical Property by Novel High-Resolution Doppler Method -Quantitative Relationship between Multiple Risk Index and Physical Property of Arterial Wall in the Group Medical Examination

在本项目中，我们进一步改进了非侵入性高分辨率诊断方法--阶段跟踪法，将其应用于集体体检，用于测量动脉粥样硬化局部、10微米级的病理变化。我们还检查了Framingham报告中提出的每个动脉硬化危险因素或多个危险指数与颈动脉病理损害以及颈动脉斑块的动脉内物理性质之间的关系。以下是本项目的结果：1.我们能够准确地评估动脉壁厚度的局部硬化性变化，心动周期期间壁厚度的瞬时变化，不仅跨整个壁厚度，而且跨整个壁厚度的适当的局部弹性硬度。这些测量可以在5分钟内完成，并成为真正的常规诊断方法。动脉硬化最早的改变是固有壁的改变，而不是以往报道所认为的管壁增厚。使用这种方法，我们可以评估动脉粥样斑块内部的物理性质。斑块的基本物理特征表明，较硬的盖子表面覆盖了顺应性较强的材料内部。在危险指数的控制下，动脉粥样斑块的物理性质在相对较短的几周内发生了变化，斑块的稳定性被认为是急性冠状动脉综合征的关键因素。开发的无创多普勒技术提供了斑块上每一层的粘弹值和物理稳定性的信息。这种新的多普勒方法将有助于在集体临床检查中进行健康教育，并通过药物治疗明确局部动脉粥样硬化病变的变化情况。

In this project, we further improved the non-invasive high-resolution diagnostic method "Phased Tracking Method" for the clinical modality to measure regional, tenth micron-order pathological change of the arterioatherosclerosis, applying the method for the group medical examination. We also examined relationships between each areteriosclerotic risk factor or the multiple risk index proposed in Framingham report and the pathological lesion at carotid artery as well as the intra-atheromatous physical property of the carotid arterial plaque.Followings are results form this project ;1. We become able to evaluate precisely the regional sclerotic change of the arterial wall thickness, the instantaneous change in the wall thickness during the cardiac cycle, proper regional elastic stiffness snot only across the entire wall thickness but also of each tenth-micron thickness layer across the wall. These measurements could be accomplished within 5 minutes and become real routine diagnostic method.2. The earliest change of the arteriosclerosis was the change in the proper wall, not the thickening of the wall as believed in the previous report.3. Using this method, we can evaluate the physical nature inside the atheromatous plaque. The basic physical feature of the plaque suggested that the stiffer cap covered superficially the much compliant material interior.4. The physical nature of the atheromatous plaque changed within relatively short period of several weeks by the control of the risk index.The stability of the atheromatous plaque has been suggested to be the key factor of the acute coronary syndrome. The non-invasive Doppler technique developed here supplies the information of the visco-elastic value at each layer across the plaque and physical stability. The novel Doppler method would be useful for the health care education in the group clinical examination and clarify the changing aspect of the regional atheromatous lesion through the medical therapy.