NMR AND MR IMAGING STUDIES OF PLAQUE RUPTURE

尽管在检测和治疗方面取得了进展 血管疾病，心肌梗死和中风经常发作 明显健康的人在没有警告的情况下产生残疾或死亡。 动脉粥样硬化是大多数心脏病发作和中风的根本原因。 动脉粥样硬化斑块会随着时间的推移缓慢生长，并逐渐阻塞血液。 流动，通常会产生警告患者潜在疾病的症状。 然而，闭塞程度较低的斑块可以在几分钟内通过以下方式产生急性事件 破裂并突然形成闭塞性血栓。这些斑块似乎 具有某些物理特征，如薄纤维帽和 富含脂质的核心，这将它们与不太危险的斑块区分开来。的确有 通过成像方法评估人类血管疾病的新紧迫性 提供有关斑块超微结构的数据，而不是侵入性方法 例如仅报告管腔狭窄的血管造影术。此项目使用 改良康斯坦丁动物(兔)斑块破裂模型的比较 未破裂斑块和破裂斑块的斑块成分和超微结构。 兔(活体)主动脉的磁共振(MR)图像将是 在触发斑块破裂前和之后获得，9与更高 决议)切除后。破裂型与非破裂型的磁共振图像比较 未破裂的斑块将提供斑块破裂的标志物，并确定 磁共振成像对预测易损斑块的价值将为 斑块破裂及磁共振成像对易损性的预测价值 在破裂发生之前，人类的斑块。魔角旋转(MAS)核磁共振 光谱学将被用来现场表征每种脂类的组成 切除斑块的阶段性变化。MAS核磁共振仪可以定量测定晶体 胆固醇、液体和液晶胆固醇酯以及钙 完整斑块中的盐；这些结构中的每一个单独或相互作用 二者之间，可能在斑块易感性中起到一定作用。为了增强 解释磁共振图像，详细的物理化学信息来自 MAS核磁共振将与脂肪和蛋白质的空间信息相结合 由磁共振(MR)成像和光确定的成分 显微镜/组织学。因为斑块的超微结构似乎是关键 由于它们的稳定性和回归的可能性，磁共振成像具有潜在的 作为急性病理事件(心脏病发作)更可靠的预测指标 和中风)。

Although the advances have been made in the detection and treatment of vascular diseases, myocardial infarctions and strokes often strike apparently healthy persons without warning and produce disabilities or death. Atherosclerosis is the underlying cause of most heart attacks and strokes. Atherosclerotic plaques can grow slowly over time and gradually block blood flow, often producing symptoms that warn the patient of the underlying disease. However, less occlusive plaques can produce acute events within minutes by rupturing and abruptly forming an occlusive thrombus. These plaques appear to have certain physical characteristics, such as a thin fibrous cap and lipid-rich core, which distinguish them from less dangerous plaques. There is new urgency to evaluate vascular disease in humans by imaging methods that provide data about the ultrastructure of plaques, rather than invasive methods such as angiography that report only luminal narrowing. This project uses the modified Constantinides animal (rabbit) model of plaque rupture to compare plaque components and ultrastructure in non-ruptured and ruptured plaques. Magnetic resonance (MR) images of the aorta in rabbits (in vivo) will be obtained before and after triggering plaque rupture, and 9with higher resolution) after excision. Comparison of the MR images of ruptured and non-ruptured plaques will provide markers for plaque rupture and determine the value of MR imaging for predicting vulnerable plaques will provide markers for plaque rupture and determine the value of MR imaging for predicting vulnerable plaques in humans before rupture occurs. Magic angle spinning (MAS) NMR spectroscopy will be used to characterize in situ the composition of each lipid phase in excised plaques. MAS NMR allows quantitation of crystalline cholesterol, liquid and liquid-crystalline cholesteryl esters, and calcium salts in the intact plaque; each of these structures alone, or interactions between them, may play a role in plaque vulnerability. To enhance the interpretation of MR images, the detailed physical chemical information from MAS NMR will be integrated with the spatial information about lipid and protein components determined by magnetic resonance (MR) imaging and light microscopy/histology. Because the ultrastructure of plaques appears to be key to their stability and potential for regression, MR imaging has the potential for being a more reliable predictor of acute pathological events (heart attack and stroke).