MR IMAGING OF THE VULNERABLE PLAQUE

描述 (改编自申请者摘要)本项目的总体目标是 开发磁共振成像方法来识别生化成分和 动脉粥样硬化斑块的体内外生物物理特性 这将通过映射异类 生物材料在斑块中的分布，包括蛋白质，脂类， 钙和血液产品。目前，来自美国的质子信号 大分子在常规的活体成像中是看不到的， 光谱学。研究人员在这一应用中提出了开发 和优化磁化传递对比度(MTC)，这是一种 合理固定的大分子存在的灵敏指示器， 因此，最适合于检测动脉粥样硬化中的纤维帽。上一首 研究表明，脆弱的病变是由一种薄纤维组成的。 围着一个大的脂水池的帽子。水信号对水的依赖性 磁化转移准备脉冲的频率形成 揭示磁共振线宽和线形的交叉弛豫分布 看不见的大分子能够识别帽子内的变化 这将是炎症反应区域的信号，因此是易感性的信号。 破裂。此外，脂类在体内的运动动力学 动脉粥样硬化粥也通过磁性交叉松弛来测量 周围的水质子。磁共振成像技术的研究进展 将实现对易受攻击的动脉粥样硬化斑块成分的解决 通过以下方式：1)在模拟主要 动脉粥样硬化的成分，表征了动脉粥样硬化的生物物理机制 离体人不同条件下的磁化传递(MT)2 用高分辨率核磁共振显微成像直接检测动脉和 固体、半固体和液体成分在9.4T下的光谱 由于它们的分子间磁性交叉弛豫和个体弛豫 以确定这些指标与斑块特征的关系，例如 分期和炎症反应的存在。3)体内发育 使用优化的磁共振序列在3特斯拉进行动脉粥样硬化血管成像。 检查计划接受颈动脉治疗的患者的颈动脉动脉粥样硬化 动脉内膜切除术，并检查动脉粥样硬化标本的斑块形态计量学 和免疫组织化学。他们还将开发新的方法来 评价斑块原位钙化以确定化学成分 磷酸钙的组成。

DESCRIPTION (Adapted from Applicant's Abstract) The overall goal of this project is to develop MR imaging methods to identify the biochemical components and biophysical characteristics of atherosclerotic plaques in vitro and in vivo This will be accomplished through the mapping of the heterogeneous distribution of biomaterials in plaques which include proteins, lipids, calcium and blood products. Currently, the proton signal from macromolecules is unobservable in conventional in vivo imaging and spectroscopy. The investigators propose in this application the development and optimization of magnetization transfer contrast (MTC) that is a sensitive indicator of the presence of rationally immobilized macromolecule, and therefore, optimum for detection of a fibrous cap in atheroma. Previous studies suggest that the vulnerable lesion is one composed of a thin fibrous cap surrounding a large lipid pool. The dependence of the water signal on the frequency of the magnetization transfer preparation pulse forms a cross-relaxation profile that reveals the linewidth the lineshape of the MR invisible macromolecule enabling identification of variations within the cap that will signal regions of inflammatory response, and thus susceptibility to rupture. Additionally, the motional dynamics of the lipids in the atheromatous gruel are also measured through magnetic cross-relaxation to the surrounding water protons. Development of the MR techniques for resolving the vulnerable atherosclerotic plaque components will be achieved by the following: 1) In lipid and protein phantoms that model the major components of atheroma, characterize the biophysical mechanism of magnetization transfer (MT under various conditions, 2) In excised human arteries directly detect with high resolution NMR microimaging and spectroscopy at 9.4 T the solid, semi-solid, and liquid components as well as their inter-molecular magnetic cross-relaxation and individual relaxation rates to establish how these relate to plaque characteristics such as staging and presence of inflammatory response. 3) Develop in vivo atherosclerotic vascular imaging at 3 Tesla using optimized MR sequences. Examine carotid artery atheromas in patients scheduled for carotid endarterectomy, and examine atherectomy specimens for plaque morphometrics and immunohistochemistry. They will also develop novel methods for evaluating in situ plaque calcification to determine the chemical composition of the calcium phosphate.