Intravascular Photothermal Strain Imaging for Lipid Detection

Area of Science:

• Biomedical Engineering
• Medical Imaging
• Cardiovascular Research

Background:

• Cardiovascular disease (CVD) causes significant global mortality.
• Plaque rupture in high-risk CVD patients is a critical concern.
• Accurate assessment of plaque stability, particularly lipid content, is crucial for risk stratification, but current intravascular imaging methods have limitations.

Purpose of the Study:

• To introduce and evaluate a novel intravascular photothermal strain imaging (pTSI) system for detecting lipids within atherosclerotic plaques.
• To assess the feasibility of integrating pTSI with conventional intravascular ultrasound (US) for enhanced plaque characterization.

Main Methods:

• Developed an intravascular imaging system combining laser-induced heating and ultrasound.
• Designed an intravascular catheter capable of delivering a 1210-nm laser and US simultaneously.
• Utilized the principle of temperature-dependent ultrasound velocity changes to differentiate tissue types.
• Validated the system using a tissue-mimicking phantom composed of fat and gelatin.

Main Results:

• The pTSI system successfully differentiated between fat and gelatin in the phantom based on strain differences during laser heating.
• Demonstrated the capability of pTSI to distinguish lipid-rich tissues from other materials.
• Confirmed the feasibility of simultaneous laser delivery and US acquisition within an intravascular catheter.

Conclusions:

• The novel intravascular pTSI technique shows promise for detecting plaque lipids.
• pTSI can be integrated with existing intravascular imaging modalities to improve cardiovascular risk assessment.
• This technology offers a potential advancement in identifying vulnerable plaques for targeted intervention.