Dual modality intravascular catheter system combining pulse-sampling fluorescence lifetime imaging and...

Area of Science:

• Cardiovascular Imaging
• Biomedical Engineering
• Optical Physics

Background:

• Coronary artery disease management and acute coronary syndrome prevention depend on understanding atherosclerotic plaque pathobiology.
• Current imaging methods may lack comprehensive assessment of both biochemical and morphological plaque features.

Purpose of the Study:

• To develop and implement a novel intravascular catheter system integrating fluorescence lifetime imaging (FLIm) and polarization-sensitive optical coherence tomography (PSOCT).
• To enable multi-scale assessment of plaque structure and composition without molecular contrast agents.

Main Methods:

• A low-profile (2.7 Fr) catheter utilizing a double-clad fiber (DCF) and a broadband, high return loss rotary junction was engineered.
• The system was optimized to mitigate OCT performance reduction from reflections and multipath artifacts.
• Simultaneous co-registered FLIm data across four spectral bands and PSOCT parameters (intensity, birefringence, depolarization) were acquired.

Main Results:

• The FLIm-PSOCT catheter system successfully acquired multi-modal data in phantoms, ex vivo swine coronary specimens, and in vivo swine hearts.
• The system demonstrated high-speed operation (100 fps B-scan, 40 mm/s pullback).
• Complementary tissue information including morphology, extracellular matrix composition, and inflammation markers was obtained.

Conclusions:

• This first-in-class hybrid FLIm-PSOCT intravascular catheter provides a comprehensive, multi-scale assessment of atherosclerotic plaques.
• The device's suitability for percutaneous coronary intervention opens new avenues for cardiovascular research and clinical diagnosis.