Human coronary atherosclerosis studied by morphological NIR Raman confocal microspectroscopy

We used Raman microspectroscopy to study all major morphological structures from normal and atherosclerotic tissue expressing different stages of disease. Thin sections (6 mu m) from coronary artery samples were studied with a Raman microspectrometer system. Raman spectra were collected from the internal and external elastic lamina, collagen fibers/fibrous cap, foam cells, smooth muscle cells, necrotic core, adventitial fat, beta-carotene containing crystals, cholesterol crystals and calcium mineralizations. To assess the chemical composition of the examined morphological structures each spectrum was modeled with a chemical algorithm containing the Raman spectra of the major chemicals present in artery wall. The results of this analysis show that the chemical composition of each morphological structure is well defined and shows little variation between similar structures from different samples.