MRI IN VIVO DETECTION OF UNSTABLE ATHEROSCLEROTIC PLAQUE

描述高分辨率磁共振成像（MRI），以识别 颈动脉分叉处动脉粥样硬化斑块的特征， 预测患者的临床进程。 拟议的研究将 确定体内MRI检测的灵敏度和特异性 人颈动脉分叉处与斑块相关的斑块特征 不稳定 颈动脉的高分辨率MRI， 颈动脉内膜切除术将允许MR图像的直接关联， 组织学特征 这反过来又会导致筛查和 高风险个体的后续行动，并允许医疗和手术 在出现短暂性颈动脉粥样硬化之前纠正不稳定的颈动脉斑块 缺血性发作或中风。 为了确定MRI是否可以确定 动脉粥样硬化斑块的纤维帽是完整的， 高分辨率黑血成像技术的实现将 用于识别和定义组织对比度的差异（包括 形成火山口形状），这些MR 图像与组织切片比较（Aim 1）。 之间的相关性 MRI检测到纤维帽破裂，缺血性神经功能增加 症状，将由MR时的临床表现确定 检查（包括无症状患者，可能斑块较少 破裂/症状），动脉内膜切除术时的症状状态， 组织学特征（目的2）。 为了确定MR图像是否可以识别 新发斑块内出血（IH）和组织性IH，不同实施方式 高分辨率的黑血成像技术将用于识别 将IH与其他组织区分开的对比特征以及新的 组织IH和比较这些MR图像与组织切片 (Aim 3）。 最后，比较MRI结果与症状状态 包括组织学检查，将决定是否有 缺血性神经系统事件的近期病史显示， 近期IH（目标4）。 在拟议的5年期间，将对150名手术患者进行研究 问题研究 MRI、组织学和症状之间的所有相关性 每名患者的状态将由独立观察员使用 双盲方案。 纤维帽断裂的准确诊断和 斑块内出血/血栓可能具有特殊临床相关性， 这些事件被认为先于并导致血栓栓塞性闭塞， 可能导致中风 这些研究可能 最终导致结构的可靠可视化 在体颈动脉粥样硬化晚期病变的特点 这可以提供一种非侵入性机制来检测可能发生的病变， 中风风险更高的人。

DESCRIPTION high resolution magnetic resonance imaging (MRI) to identify the characteristics of carotid bifurcation atherosclerotic plaques and thus predict the clinical course of patients. The proposed studies will determine the sensitivity and specificity of in vivo MRI in the detection of plaque features at the human carotid bifurcation that are linked to plaque instability. High resolution MRI of the carotid artery immediately prior to carotid endarterectomy will allow direct correlation of MR images and histologic features. This in turn will lead to strategies for screening and follow-up of high risk individuals and would allow medical and surgical correction of unstable carotid plaques prior to the development of transient ischemic attacks or stroke. To determine whether MRI can determine if the fibrous cap of an atherosclerotic plaque is intact, different implementations of high resolution black blood imaging techniques will be used to identify and define differences in tissue contrast (including formation of a crater shape) on the luminal plaque surface and these MR images compared with histologic sections (Aim 1). Correlations between fibrous cap rupture, as detected by MRI, and increased ischemic neurologic symptoms, will be determined by the clinical presentation at the time of MR exam (including asymptomatic patients, presumably with less plaque rupture/symptoms), symptomatic status at the time of endarterectomy and histologic features (Aim 2). To determine whether MR images can identify new intraplaque hemorrhage (IH) and organized IH, different implementations of high resolution black blood imaging techniques will be used to identify the contrast features that differentiate IH from other tissues and new from organized IH and by comparison of these MR images with histologic sections (Aim 3). Finally, comparison of the MRI findings to the symptomatic status of the patient, including histology, will determine whether patients with a recent history of ischemic neurologic events show increased evidence of recent IH (Aim 4). A series of 150 surgery patients will be studied during the proposed 5-year studies. All the correlations between the MRI, histology and symptomatic status of each patient will be performed by independent observers, using a double-blind protocol. The accurate diagnosis of fibrous cap rupture and intraplaque hemorrhage/thrombus may have particular clinical relevance since these events are thought to precede and cause thromboembolic occlusion, which in the carotid artery, may result in stroke. These studies may eventually lead to the reliable visualization of the structural characteristics of advance lesions of carotid artery atherosclerosis in vivo which may provide a noninvasive mechanism to detect lesions that may place individuals at greater risk for stroke.