DETECTION OF VULNERABLE PLAQUES USING RAMAN, FLUORESCENCE AND REFLECTANCE SPECT

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 易损斑块的形态特征为：纤维帽变薄或溃烂，核心大片坏死，表面有泡沫细胞，斑块内出血。我们主张使用多模式光谱方法，包括拉曼光谱、漫反射光谱和本征荧光光谱，来检测这些易损斑块的关键形态标志。本文对17例人颈动脉标本进行了体外初步研究。在获得光谱后，对每个标本进行组织学评估。从漫反射光谱获得的参数、血红蛋白浓度和散射参数被确定为可以分别用于检测斑块内出血和泡沫细胞。从本征荧光中提取的与组织最顶层中的胶原蛋白含量有关的参数可以用来检测薄纤维帽的存在。最后，与胆固醇和坏死物的量有关的拉曼光谱参数可能被用来检测坏死核。多峰光谱学方法在提供斑块成分的深度敏感和互补的形态信息方面显示出巨大的潜力。需要一项更大规模的研究来进一步验证诊断易损斑块的可能性，这将是我们未来工作的重点。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Vulnerable plaques are characterized by morphological features such as a thin or ulcerated fibrous cap, a large necrotic core, superficial foam cells, and intraplaque hemorrhage. We argue for the use of a multimodal spectroscopic method, comprising Raman, diffuse reflectance, and intrinsic fluorescence spectroscopy, to detect these key morphological markers of vulnerable plaque. A preliminary study was performed in vitro on 17 human carotid artery specimens. Following the acquisition of the spectra, each specimen was histologically evaluated. It was determined that parameters obtained from diffuse reflectance spectroscopy, the hemoglobin concentration and the scattering parameter, can potentially be used to detect intraplaque hemorrhage and foam cells, respectively. A parameter extracted from the intrinsic fluorescence that relates to the amount of collagen in the topmost layers of the tissue can be used to sense the presence of a thin fibrous cap. Finally, a Raman spectroscopy parameter related to the amount of cholesterol and necrotic material can potentially be used to detect a necrotic core. The multimodal spectroscopy method shows great promise to provide depth-sensitive and complementary morphological information about plaque composition. A larger study is needed to further validate the potential for diagnosis of vulnerable plaque and this shall be the focus of our future work.