NEAR-INFRARED FOURIER-TRANSFORM RAMAN-SPECTROSCOPY OF HUMAN ARTERY

We report the first near IR FT-Raman spectroscopy of normal and diseased human artery. In normal human aorta, two bands at 1669 cm-1 and 1452 cm-1 dominate the spectrum and can be assigned to protein amide I and C-H in-plane bending vibrations, respectively. Weaker bands are also observed between 1250 and 1350 cm-1. Non-calcified atherosclerotic lesions with a large amount of necrotic debris below the tissue surface show a relative increase in the intensity of the 1452 cm-1 band. In atherosclerotic aortas which contain calcified deposits several hundred microns below the tissue surface, a strong 961 cm-1 band is observed due to the symmetric stretch of phosphate groups in the calcified salts. The results show that this method provides the capability to probe biological substituents several hundred microns below the tissue surface.