MRI IN VIVO DETECTION OF UNSTABLE ATHEROSCLEROTIC PLAQUE

描述高分辨率磁共振成像(MRI)以识别 颈动脉分叉部动脉粥样硬化斑块的特征 预测患者的临床病程。拟议的研究将 确定活体MRI检测食管瘤的敏感性和特异性 人类颈动脉分叉处与斑块相关的斑块特征 不稳定。颈动脉的高分辨率磁共振成像 颈动脉内膜切除术将使磁共振图像和 组织学特征。这反过来将导致筛查和 对高危个体进行跟踪，并允许内科和外科手术 暂时性颈动脉斑块形成前不稳定斑块的纠正 缺血性发作或中风。以确定核磁共振是否可以确定 动脉粥样硬化斑块的纤维帽是完整的，不同的 高分辨率黑血成像技术的实施将是 用于识别和定义组织对比度的差异(包括 在管腔斑块表面形成陨石坑形状)和这些MR 图像与组织切片对照(目标1)。两者之间的相关性 MRI检测到的纤维帽破裂和缺血性神经病变的增加 症状，将由磁共振检查时的临床表现决定。 检查(包括无症状的患者，估计斑块较少 破裂/症状)、动脉内膜切除术时的症状状态以及 组织学特征(目标2)。以确定磁共振图像是否可以识别 新斑块内出血(IH)和有组织IH，不同的实施方案 高分辨率黑血成像技术将被用来识别 IH区别于其他组织和新的组织的对比特征 并将这些MRI图像与组织切片进行比较 (目标3)。最后，将MRI表现与症状状态进行比较。 包括组织学，将决定患者是否患有 最近的缺血性神经事件史显示有更多的证据表明 最近的IH(目标4)。 在拟议的5年内，将对150名手术患者进行一系列研究 学习。MRI、组织学和症状之间的所有相关性 每个患者的状态将由独立的观察员执行，使用 双盲协议。纤维帽断裂的准确诊断及临床意义 斑块内出血/血栓可能具有特殊的临床相关性，因为 这些事件被认为先于血栓闭塞并导致血栓闭塞， 在颈动脉，可能会导致中风。这些研究可能 最终导致结构的可靠可视化 颈动脉粥样硬化进展期病变的在体特点 其可以提供一种非侵入性机制来检测可能 中风风险较高的个体。

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.