Mechanical characterization of carotid plaques for stroke risk assessment

中风是第五大死亡原因，也是可预防的残疾的主要原因 根据《美国心脏》的最新统计数据，美国的住院情况 协会。每年，约有795,000人继续经历新的或复发的 卒中。平均每40秒，美国就有一个人中风，而另一个人 大约每4分钟就死一例。死亡率如此之高，部分原因是 最先进的方法，如CT，MRI和超声波目前无法提供信息 及时干预。高危、无症状颈动脉斑块患者的鉴别 因此，它们的低狭窄仍然是预防中风的一个难以捉摸但必不可少的步骤。在当前 临床实践中，颈动脉斑块破裂的风险评估是基于颈动脉内膜的程度-- 中层厚度(IMT)和管腔内狭窄，尽管它们不一定 与易损斑块或随后的破裂有关。因此，目前的临床模式还不够完善 在告知斑块稳定性方面。有关斑块稳定性的可靠信息将确保及时 治疗，特别是对无症状或有中风风险的低度腔内狭窄患者 仍然严重低估了诊断。这些信息被证明是关键的，但在临床上是不可用的 在于斑块的顺应性和相关的血流。脂斑块(典型的 稳定性较差，并与缺血性中风有关)已被证明具有明显的僵硬 是钙化斑块造成的。据报道，中风患者的动脉僵硬也有所增加。这个 因此，拟议的研究的目的是通过优化颈动脉超声检查 PWI和VFI相结合的方法(PWI+VFI)和量化遵从性的生物标志物 和流动，以提供有关斑块稳定性的关键生物力学信息。在报告中 研究表明，在大型动物和中风患者中，斑块的特征 是可以实现的。我们已经证明PWI+VFI能够表征颈动脉 斑块基于其独特的硬度和流动性。在本研究中，我们的目标是 颈动脉斑块的特征用于最终可靠地评估缺血性卒中风险 基于斑块壁和血流生物标记物。因此，我们假设PWI可以显著地 增强常规血管超声的诊断能力。集结的团队是 高度多学科，包括超声成像、生物力学、血管 放射学、病理学、神经学、血管外科和生物统计学。遵循建议的 研究表明，这种高度平移的技术可以很容易地集成到标准的超声波图中 准确告知颈动脉斑块的稳定性，从而及时进行后续治疗。

Stroke is the fifth leading cause of death and the primary cause of preventable disability and hospitalization in the U.S according to the most recent statistics by the American Heart Association. Each year, approximately 795,000 people continue to experience a new or recurrent stroke. On average, every 40 seconds, someone in the United States has a stroke, and someone dies of one approximately every 4 minutes. This high fatality rate is partly due to the fact that state-of-the-art methodologies such as CT, MRI and ultrasound are currently failing to inform timely intervention. Identification of patients with high-risk, asymptomatic carotid plaques despite their low stenoses remains thus an elusive but essential step in stroke prevention. In current clinical practice, the risk assessment of carotid plaque rupture is based on the degree of intima- media thickness (IMT) and endoluminal stenosis despite the fact that they do not necessarily correlate with vulnerable plaques or subsequent rupture. Current clinical modalities fall thus short in informing on plaque stability. Reliable information on plaque stability would ensure timely treatment, especially in asymptomatic or low endoluminal stenosis patients whose stroke risk remains severely underdiagnosed. Such information shown to be critical but clinically unavailable lies in the plaque compliance and the associated blood flow. Lipid plaques (which are typically less stable and are associated with ischemic stroke) have been shown to have distinct stiffness from calcified plaques. Increased arterial stiffness has also been reported in stroke patients. The objective of the proposed study is thus to amplify the role of carotid sonography by optimizing the combined PWI and VFI methodologies (PWI+VFI) and quantifying the biomarkers of compliance and flow in order to provide critical biomechanical information on plaque stability. In reported studies, our group has shown that plaque characterization in large animals and stroke patients can be achieved. We have demonstrated that PWI+VFI is capable of characterizing carotid plaques based on their distinct stiffness and flow. In this study, we aim towards the characterization of carotid plaques for the ultimately reliable assessment of ischemic stroke risk based on plaque wall and flow biomarkers. We thus hypothesize that PWI can significantly reinforce the diagnostic capability of a conventional vascular ultrasound. The team assembled is highly multi-disciplinary encompassing expertise in ultrasound imaging, biomechanics, vascular radiology, pathology, neurology, vascular surgery and biostatistics. Following the proposed studies, this highly translational technology could be readily integrated in a standard sonogram to accurately inform carotid plaque stability and thus subsequent timely treatment.