Spectroscopic characterisation of carotid atherosclerotic plaque by laser induced fluorescence

Background and Objective An effort has been made to distinguish the composition of carotid atherosclerotic plaques (CAP) from patients undergoing carotid endarterectomy, by laser induced fluorescence spectroscopy. Study Design/Materials and Methods Different excitation wavelengths were used: 476, 488, and 458 nm of a continuous wave krypton/argon ion laser, and 337 nm of a pulsed nitrogen laser. Twenty‐three CAP samples from different patients were investigated and several spectra from each plaque were obtained. Results Results were crossed‐examined with conventional histologic techniques, which showed three areas of different composition on the pathologic samples: fibrous tissue, lipid constituents, and calcified plaque. Gaussian fittings were performed to reproduce the fluorescence spectra as a correlation of multiple Gaussian curves. Conclusion The accuracy for discrimination of the heterogeneous composition of the atherosclerotic plaque is still limited, due to superposition of the fluorescence emission of various plaque components. Lasers Surg. Med. 28:67–73, 2001. © 2001 Wiley‐Liss, Inc.