MRI IDENTIFICATION--HIGH RISK ATHEROSCLEROTIC PLAQUES

动脉粥样硬化引起的心血管疾病仍然是主要原因 在美国的死亡。临床症状和发病率 动脉粥样硬化性疾病是由于斑块不稳定和 表现为溃疡、血栓形成和/或斑块内出血。 许多研究都是为了了解动脉粥样硬化的形成， 疾病的进展和导致心脏的最终事件 发作或中风。然而，人们对如何执行以下操作知之甚少 在活体内无创识别高危病变并监测 病变纵向进展。这项提案提出了一项计划，以 测量MRI图像中动脉粥样硬化斑块的体积，并评估 磁共振在检测相关斑块特征方面的能力 有临床症状。我们把研究重点放在晚期病变上 颈动脉分叉：1)与卒中密切相关；2) 它们可通过高分辨率MRI技术获得，以及3) 颈动脉内膜切除术后颈动脉样本的可及性 为我们提供了通过以下方式验证MRI结果的绝佳机会 对样本进行组织学检查。 该项目的长期目标是将高分辨率MRI用于 血流动力学显著(大于70%)的患者 直径缩小)颈动脉狭窄以区分那些 会导致血栓形成/栓塞和中风的发展。在… 目前还没有可靠的方法来测量斑块的体积 活体或评估体内斑块的特征。这个 具体目标是：1)测试体内核磁共振是否可以用来测量 动脉粥样硬化体积，以及2)测试体内MRI是否可以 鉴别有薄纤维帽和坏死核的病变。我们建议 目的：确定MRI斑块体积测量的准确性和斑块体积的大小 磁共振成像对不同类型肿瘤诊断的敏感性和特异性 损伤的数量。不同斑块类型的准确诊断具有特殊性 临床相关性，如软化的纤维帽覆盖坏死灶 被认为是结构薄弱的，可能先于斑块事件 破裂和血栓栓塞性闭塞，在颈动脉可能 会导致中风。能够准确测量斑块体积和 鉴别晚期皮损的结构特点 体内动脉粥样硬化可能提供一种非侵入性机制 斑块进展的演变和检测可能使斑块 临床事件风险较大的个人。

Cardiovascular disease due to atherosclerosis remains the leading cause of death in the United States. Clinical symptoms and morbidity that result from atherosclerotic disease are due to plaque instability and are manifested as ulceration, thrombosis and/or intraplaque hemorrhage. Much research has been directed at understanding the atherogenesis, the progression of the disease and the final events that lead to heart attack or stroke. However, relatively little is known about how to identify high risk lesions in vivo noninvasively and to monitor the lesion progression longitudinally. This proposal presents a plan to measure the atherosclerotic plaque volume in MR images and to assess the power of MRI in detecting plaque characteristics that are associated with clinical symptoms. We focus our study on advanced lesions at the carotid bifurcation due to 1) their close association to stroke, 2) their accessibility by high resolution MRI techniques, and 3) the accessibility of carotid samples due to carotid endarterectomy that provides us with excellent opportunity to verify the MRI results by examining the samples histologically. The long term goal of this project is to use high resolution MRI in patients with hemodynamically significant (greater than 70 percent diameter reduction) carotid stenoses to differentiate those plaques that will lead to the development of thrombosis/embolization and stroke. At present there are no reliable means to either measure the plaque volume in vivo or to assess the characteristics of plaques in vivo. The specific aims are: 1) to test whether in vivo MRI can be used to measure the atherosclerotic volume, and 2) to test whether in vivo MRI can identify lesions with thin fibrous cap and a necrotic core. We propose to determine the accuracy of MRI plaque volume measurement and the sensitivity and specificity of MRI in the detection of different types of lesions. Accurate diagnosis of different plaque types has particular clinical relevance, as a weakened fibrous cap covering a necrotic core is thought to be structually weak, and may precede the events of plaque rupture and thromboembolic occlusion, which in the carotid artery may result in stroke. The ability to accurately measure plaque volumes and to distinguish the structural characteristics of advanced lesions of atherosclerosis in vivo may provide a noninvasive mechanism to follow the evolution of plaque progression and to detect lesions that may put individuals at greater risk of clinical events.