Dual modality instrument for simultaneous optical coherence tomography imaging and fluorescence spectroscopy

Area of Science:

• Biomedical Optics
• Medical Imaging
• Spectroscopy

Background:

• Atherosclerosis diagnosis relies on imaging and biochemical analysis.
• Existing methods may lack the resolution or specificity for early detection.
• A combined approach could offer comprehensive tissue characterization.

Purpose of the Study:

• To develop and evaluate a dual-modality device integrating optical coherence tomography (OCT) and laser-induced fluorescence (LIF) spectroscopy.
• To assess the device's capability in differentiating normal and atherosclerotic aorta tissues.
• To explore the potential of this combined technology for plaque characterization.

Main Methods:

• A dual-modality system was engineered, combining OCT (1300 nm) for structural imaging and LIF spectroscopy (325/442 nm excitation) for biochemical analysis.
• The device was tested on eight postmortem aorta samples.
• OCT provided cross-sectional images, while LIF yielded emission spectra for analysis.

Main Results:

• OCT images revealed distinct tissue layers (intima, media) and fibrotic regions in the aorta wall.
• LIF spectroscopy, using specific emission spectra ratios, achieved high classification rates for normal (97%) and plaque (91%) regions.
• Complementary structural and functional data were obtained from normal and atherosclerotic aorta segments.

Conclusions:

• The dual-modality OCT-LIF device provides complementary anatomical and biochemical information of the aorta wall.
• This technology demonstrates significant potential for accurate identification and characterization of atherosclerotic plaques.
• Further miniaturization and speed improvements could establish this device as a valuable clinical tool for atherosclerosis management.