Development of an intracoronary Raman spectroscopy

[摘要] (cont.) In contrast to previous work, which focused on plaque characterization based on the Raman spectrum from a single site within the plaque, our system utilizes a line imaging paradigm, in which we acquire Raman spectra at fixed intervals across the full cross-section of the plaque, creating a Raman line image. We use this benchtop system to acquire a database of Raman line images and corresponding histology for over sixty plaque specimens. Using this database, we compare the diagnostic capability of fingerprint and high wavenumber Raman spectroscopy for plaque characterization. Because of the small size requirement for an intracoronary probe, it is important to optimize the optical probe design to maximize collection efficiency and thus increase SNR. We develop and experimentally validate a simulation technique for modeling Raman probe performance (collection efficiency and sampling volume), as an aid to optimizing probe design. We also fabricate a 1.5 mm diameter probe and demonstrate it in vivo, using a human-swine xenograft model, in which diseased human coronary arteries are grafted onto a living swine heart. The results of this thesis provide insight on two approaches toward achieving a clinically viable intracoronary Raman spectroscopy system.

[发布机构] Massachusetts Institute of Technology