Thermoelastic displacement measured by DP-OCT for detecting vulnerable plaques

Area of Science:

• Biomedical Optics
• Medical Imaging
• Cardiovascular Research

Background:

• Atherosclerotic plaques pose a significant health risk.
• Early detection of vulnerable plaques is crucial for preventing cardiovascular events.
• Optical coherence tomography (OCT) offers high-resolution imaging, but differentiating plaque types remains challenging.

Purpose of the Study:

• To analytically evaluate the detection of thermoelastic displacement using differential phase optical coherence tomography (DP-OCT) for identifying atherosclerotic plaques.
• To understand the thermoelastic responses of MION-injected tissue to laser irradiation.
• To assess the impact of heat source distribution on displacement dynamics.

Main Methods:

• Development of analytical solutions for thermoelastic displacement.
• Modeling of point heat sources during and after laser irradiation.
• Experimental validation using MION-injected tissue.
• Integration of a scanning mirror for improved imaging.

Main Results:

• Both analytical and experimental results showed a delayed peak displacement.
• A slow decay in displacement was observed after the laser pulse.
• Heterogeneous distribution of point heat sources was identified as the cause for delayed and slow displacement.
• DP-OCT demonstrated potential for plaque characterization.

Conclusions:

• The study provides an analytical framework for understanding thermoelastic responses in MION-injected tissue.
• Heterogeneous heat source distribution significantly influences thermoelastic displacement dynamics.
• Detailed modeling of heat sources and integration of scanning mirrors can enhance the clinical applicability of DP-OCT for vulnerable plaque diagnosis.