Method for parametric imaging of attenuation by intravascular optical coherence tomography

Area of Science:

• Medical Imaging
• Biomedical Optics
• Cardiovascular Research

Background:

• Catheter-based intravascular optical coherence tomography (IVOCT) offers high-resolution visualization of atherosclerosis.
• Quantitative characterization using attenuation coefficient (AC) extraction is valuable for OCT attenuation imaging.
• Existing AC extraction methods struggle with complex arterial tissue variability in IVOCT data, limiting tissue differentiation.

Purpose of the Study:

• To propose a novel method for parametric imaging of optical attenuation by AC retrieval from IVOCT images.
• To address the limitations of existing single scattering models in differentiating complex arterial tissue types.
• To develop a general scheme for AC extraction applicable to IVOCT data acquired during cardiac catheterization.

Main Methods:

• A multiple scattering model was employed for AC retrieval from IVOCT images.
• Monte Carlo simulation was used to physically model the OCT signal characterized by AC.
• Pixel-wise AC retrieval was achieved by iteratively minimizing an error function between modeled and measured backscattered signals.

Main Results:

• The proposed method provides a general scheme for AC extraction without requiring complete light attenuation.
• Computer-simulated and clinical image results demonstrated avoidance of overestimation at the end of the depth profile compared to depth-resolved (DR) models.
• Energy error depth and structural similarity were improved by approximately 30% and 10%, respectively, compared to DR models.

Conclusions:

• The novel multiple scattering model-based method offers improved AC retrieval for IVOCT images.
• This approach enhances the differentiation and characterization of arterial tissue types in IVOCT imaging.
• The method provides a more robust quantitative analysis of atherosclerotic plaques and vessel structures.