Simultaneous Morphological and Flow Imaging Enabled by Megahertz Intravascular Doppler Optical Coherence Tomography

Area of Science:

• Medical Imaging
• Biomedical Engineering
• Cardiovascular Technology

Background:

• Intravascular imaging is crucial for diagnosing cardiovascular diseases.
• Current methods often lack the speed and resolution for comprehensive flow analysis.
• Optical Coherence Tomography (OCT) offers high-resolution imaging but struggles with fast flow quantification.

Purpose of the Study:

• To develop and validate a 3D intravascular Doppler Optical Coherence Tomography (OCT) system for clinical compatibility.
• To enable simultaneous high-speed 3D morphological and Doppler flow imaging.
• To improve the assessment of coronary artery blood flow dynamics.

Main Methods:

• Utilized a megahertz (MHz) Fourier Domain Mode Locked (FDML) laser and a 1.1 mm motorized catheter for OCT imaging.
• Implemented a post-processing method to compensate for laser drift and resolve Doppler phase shifts.
• Achieved high frame rates (600 frames/s) and pullback speeds (40 mm/s) for volumetric data acquisition.

Main Results:

• Demonstrated real-time 3D intravascular flow imaging with MHz OCT.
• Successfully measured flow velocities up to 37.5 cm/s without phase-unwrapping.
• Presented the first simultaneous 3D morphological images and Doppler flow profiles.
• Enabled flow pattern estimation and 3D structural reconstruction from a single pullback dataset.

Conclusions:

• The developed MHz OCT system provides a clinically compatible platform for advanced 3D intravascular flow imaging.
• This technology significantly enhances the ability to visualize and analyze coronary artery hemodynamics.
• Offers a powerful tool for improved diagnosis and treatment planning in cardiovascular medicine.