Diagnostics of the Degree of Calcification of Atherosclerotic Plaque by Laser-Induced Fluorescence

The luminescence of highly calcified atherosclerotic plaque in comparison with the luminescence of a normal wall of the vessel was studied in vitro (the luminescence was excited by a CW argon laser with λ = 488 nm or a pulsed nitrogen laser with λ = 337 nm). The mass-spectroscopy analysis of the plaque was carried out with a LAMMA-1000 system. It is ascertained that the specific shape of the luminescence spectrum with maximum at λ = 560 nm (under argon laser excitation) and λ = 485 nm (under nitrogen laser excitation) is typical of a highly calcified plaque (Ca content ≈38 %) and is similar to the luminescence spectrum of ordinary chalk.