MR IMAGING OF THE VULNERABLE PLAQUE

易损斑块的 MR 成像

• 批准号: 2756836
• 负责人: HOWARD L KANTOR
• 金额: $ 33.14万
• 依托单位: MASSACHUSETTS GENERAL HOSPITAL
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-09-30 至 2002-09-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2756836
• 关键词: atherosclerotic plaque; biophysics; carotid artery; clinical research; collagen; diagnosis design /evaluation; fibrous protein; human subject; immunocytochemistry; lipids; macromolecule; magnetic resonance imaging; method development; nuclear magnetic resonance spectroscopy; phantom model; spectrometry; structural biology

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.

描述 （根据申请人的摘要改编）该项目的总体目标是 开发MR成像方法以识别生化成分和 在体外和体内动脉粥样硬化斑块的生物物理特征 这将通过异质的映射来完成 斑块中生物材料的分布，包括蛋白质，脂质， 钙和血液产物。 目前，来自 大分子在常规的体内成像中无法观察到 光谱法。 调查人员在此应用程序中建议开发 和优化磁化转移对比度（MTC） 敏感的指标，表明存在合理固定的大分子， 因此，在动脉瘤中检测纤维帽的最佳。 以前的 研究表明，脆弱的病变是由薄纤维组成的 围绕大型脂质游泳池的帽子。 水信号的依赖性 磁化转移制备脉冲的频率形成A 交叉解释轮廓揭示了MR的线形线路的线路 无形的大分子可识别帽子内的变化 这将表明炎症反应的区域，从而敏感 破裂。 另外，脂质的运动动力学 还通过磁性交叉解释来测量动脉瘤 周围的水质子。 开发MR技术 将实现脆弱的动脉粥样硬化斑块成分 通过以下内容：1）在脂质和蛋白质幻像中建模主要 动脉瘤的成分，表征了生物物理机制 磁化转移（在各种条件下MT，2）中切除的人 动脉直接检测到高分辨率NMR微成像和 在9.4吨固体，半固体和液体成分的光谱法 由于它们的分子间磁交叉解释和个体放松 建立这些与斑块特征相关的比率 分期和炎症反应的存在。 3）体内发展 使用优化的MR序列在3特斯拉处的动脉粥样硬化血管成像。 检查计划于颈动脉的患者中的颈动脉动脉瘤 内侧切除术，并检查动脉切除术标本的斑块形态计量学 和免疫组织化学。 他们还将为 评估原位斑块钙化以确定化学物质 磷酸钙的组成。