Raman spectroscopy study of atherosclerosis in human carotid artery

Abstract

Fourier-transform (FT)-Raman spectroscopy has been used for identification and evaluation of human artherosclerotic lesions, providing biochemical information on arteries. In this work, fragments of human carotid arteries postmortem were analyzed using a FT-Raman spectrometer operating at an excitation wavelength of 1064 nm, power of 200 mW, and spectral resolution of 4 cm(-1). A total of 75 carotid fragments were spectroscopically scanned and FT-Raman results were compared with histopathology. Discriminant analysis using Mahalanobis distance was applied over principal components scores for tissue classification into three categories: nonatherosclerotic, atherosclerotic plaque without calcification and with calcification. Nonatherosclerotic artery, atherosclerotic plaque, and calcified plaque exhibit spectral signatures related to biochemicals presented in each tissue type, such as bands of collagen and elastin (proteins), cholesterol and its esters, and calcium hydroxyapatite and carbonate apatite, respectively. Spectra of nonatherosclerotic artery were then classified into two groups: normal and discrete diffuse thickening of the intima layer (first group) and moderate and intense diffuse thickening of the intima layer (second group). FT-Raman could identify and classify the tissues found in the atherosclerotic process in human carotid in vitro and had the ability to identify alterations to the diffuse thickening of the intima layer and classify it depending on the intensity of the thickening.

Near-infrared Raman spectroscopy to detect anti-Toxoplasma gondii antibody in blood sera of domestic cats: quantitative analysis based on partial least-squares multivariate statistics

“…Table 3 compares the capabilities of the dispersive Raman spectroscopy in conjunction with a multivariate statistical analysis in diagnostic models for different diseases as reported in the literature. [42][43][44][45] We can see that our results on toxoplasmosis identification agree well with those obtained for other diseases using the same spectroscopic technique.…”

Detection and Treatment of Vulnerable Plaques and Vulnerable Patients

“…Raman spectroscopy has been shown to be capable of differentiating atherosclerotic plaque from diffuse intimal thickening ex vivo in carotid endarterectomy specimens. 178 A compact fiberoptic-based Raman system for in vivo applications has been developed. 179 In autopsy studies of human coronary arteries and aortas, the system detected cholesterol and calcification in specimens.…”

Vulnerable atherosclerotic plaque detection by resonance Raman spectroscopy

“…However, there are only a few studies that have been performed using Raman spectroscopy and the vibrational frequencies of lipids for detecting atherosclerotic diseases and the thicknesses of cap layers on VPs. [10][11][12][13][14][15][16] None of these studies used resonance Raman (RR).…”

“…However, those results were only in the lower frequency spectral region of 750 to 1800 cm −1 . [12][13][14][15]26,27 This report focuses on the visible RR (VRR) technique for directly distinguishing and classifying vulnerable plaques with various states of atherosclerosis development and different cap thicknesses in human aorta tissues using RR spectral molecular fingerprints in a wide frequency region.…”