Characterization of atherosclerotic plaque depositions by Raman and FTIR imaging

Abstract

Spectroscopy-based imaging techniques can provide useful biochemical information about tissue samples. Here, we employ Raman and Fourier transform infrared (IR) imaging to characterize composition and constitution of atherosclerotic plaques of rabbits, fed with a high cholesterol diet. The results were compared with conventional light microscopy after staining with hematoxylin eosin, and elastica van Gieson. The spectral unmixing algorithm vertex component analysis was applied for data analysis and image reconstruction. IR microscopy allowed for differentiation between lipids and proteins in plaques of full aortic cross sections. Raman microscopy further discriminated cholesterol esters, cholesterol and triglycerides. FTIR and Raman images were recorded at a resolution near 20 micrometer per pixel for a large field of view. High resolution Raman images at 1 micrometer per pixel revealed structural details at selected regions of interest. The intima-media and the lipid-protein ratio were determined in five specimens for quantitation. These results correlate well with histopathology. The described method is a promising tool for easy and fast molecular imaging of atherosclerosis.

Multimodal nonlinear imaging of atherosclerotic plaques differentiation of triglyceride and cholesterol deposits

“…More detailed spectral assignments can be found in the literature. [23][24][25] For potential endoscopic in vivo applications, visualization of the arterial wall perpendicular to the blood°ow may be of interest, to address the issues of penetration depth and di®erent focal planes of CARS, TPF and SHG. In order to investigate this top viewing approach, the section adjacent to the above-described cross section was prepared as described in Sec.…”

Nanoparticle uptake by macrophages in vulnerable plaques for atherosclerosis diagnosis

“…[58] Diffusion reflection (DR) with GNP [59] Others Raman, IR (Infrared) and AFM (Atomic force microscopy) imaging [49,60] [63]. DR might be used for detection of AS plaques, prediction of disease course and therapy monitoring.…”

Electric field standing wave effects in FT-IR transflection spectra of biological tissue sections: Simulated models of experimental variability

“…Resonant and nonresonant reflection and scattering have been identified as the source of some of these effects, and correction algorithms have been developed to account for them [1][2][3][4][5][6][7]. 50 FT-IR imaging has already proven its worth in many biological applications including measurement for both cells and tissues [8][9][10][11][12][13][14][15][16]. However, measurement in transmission mode requires the use of relatively expensive IR transparent substrates (e.g.…”