Spectroscopic characterisation of carotid atherosclerotic plaque by laser induced fluorescence

Background and Objective: An effort has been made to distinguish the compos ition of carotid atherosclerotic plaques (CAP) from patients undergoing car otid endarterectomy, by laser induced fluorescence spectroscopy. Study Design/Materials and Methods: Different excitation wavelengths were u sed: 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 obtai ned. Results: Results were crossed-examined with conventional histologic techniq ues, which showed three areas of different composition on the pathologic sa mples: fibrous tissue, lipid constituents, and calcified plaque. Gaussian f ittings were performed to reproduce the fluorescence spectra as a correlati on of multiple Gaussian curves. Conclusion: The accuracy for discrimination of the heterogeneous compositio n of the atherosclerotic plaque is still limited, due to superposition of t he fluorescence emission of various plaque components. Lasers Surg. Med. 28 : 67-73, 2001. (C) 2001 Wiley-Liss, Inc.