NMR AND MR IMAGING STUDIES OF PLAQUE RUPTURE

虽然在检测和治疗方面取得了进展， 心血管疾病、心肌梗塞和中风常常发生 表面上健康的人在没有警告的情况下造成残疾或死亡。 动脉粥样硬化是大多数心脏病发作和中风的根本原因。 动脉粥样硬化斑块可以随着时间的推移缓慢增长，并逐渐阻塞血液 流动，经常产生警告患者潜在疾病的症状。 然而，较少闭塞的斑块可以在几分钟内产生急性事件， 破裂并突然形成闭塞性血栓。这些斑块似乎 具有某些物理特性，例如薄的纤维帽， 富含脂质的核心，这将它们与危险性较小的斑块区分开来。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 例如仅报告管腔变窄血管造影术。此项目使用 改良Constantinides动物（兔）斑块破裂模型比较 未破裂斑块和破裂斑块的斑块成分和超微结构。 将对家兔（体内）主动脉进行磁共振（MR）成像， 在触发斑块破裂前后， ），在切除后。破裂型与非破裂型食管癌的MR图像比较 非破裂斑块将提供斑块破裂的标志物，并确定 磁共振成像预测易损斑块的价值将为 斑块破裂及MR成像预测易损斑块的价值 在破裂发生之前的人类斑块。魔角旋转（MAS）NMR 光谱学将用于原位表征每种脂质的组成 切下的斑块阶段。MAS NMR允许定量晶体 胆固醇、液体和液晶胆固醇酯和钙 完整菌斑中的盐;这些结构中的每一个单独或相互作用 在它们之间，可能在斑块脆弱性中起作用。增强 MR图像的解释，详细的物理化学信息， MAS NMR将与脂质和蛋白质的空间信息相结合 通过磁共振（MR）成像和光 显微镜/组织学。因为斑块的超微结构似乎是 对于它们的稳定性和回归潜力，MR成像具有潜力 作为急性病理事件（心脏病发作）的更可靠的预测因子， 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).