Identification of calcifications in cardiac valves by near infrared Raman Spectroscopy

Objective: The objective of this work was to detect calcification in cardiac valves using near infrared Raman spectroscopy ( NIRS). A Ti:sapphire laser pumped by an argon-ion laser operating at a wavelength of 830 nm was used for excitation of the valve samples, and Raman emission was detected by an optical spectrometer with a liquid nitrogen-cooled CCD detector. Background: Cardiac valves are subjected to highly repetitive mechanical stresses, due to their over 40 million cardiac cycles per year. These structures may suffer cumulative lesions, complicated by the deposition of calcium phosphate, which can lead to clinically significant diseases. NIRS can provide important information about biological tissue composition and has been used for diagnosis of some types of human pathology. Methods: Samples of normal and pathologic tissues 5 mm in size were analyzed. Results: It was observed that the Raman spectrum of calcified cardiac valves presented different behavior when compared with normal valves. Differences were observed at the intensity of 960, 1260, 1452, and 1660 cm(-1) peaks. Conclusions: These results suggest that this technique could be used to detect calcium phosphate mineral deposition in cardiac valves.