Laser Induced Fluorescence in Atherosclerotic Plaque with Different Excitation Wavelengths

Laser induced fluorescence spectra were obtained from atherosclerotic plaque samples, in order to discriminate areas in the plaque of different composition. Different excitation wavelengths were used: 488nm and 476nm, provided by a c.w. Ar+ laser, 457.9nm, provided by a c.w. Kr+ laser, and 337.1nm, provided by a pulsed N2 laser. All samples were histopathologically examined and showed three areas of different composition: fibrous tissue, lipid constituents and calcified plaque. Spectra corresponding to these areas were analyzed and mathematical fittings were performed, in order to reproduce each spectrum as a correlation of multiple Gaussian peaks. An effort was made to discriminate the composition of the plaque from the information obtained by the corresponding spectra.