Acoustic Stack for Combined Intravascular Ultrasound and Photoacoustic Imaging.

Area of Science:

• Biomedical Engineering
• Medical Imaging
• Cardiovascular Technology

Background:

• Multimodal intravascular ultrasound and photoacoustic (IVUS/PA) imaging offers advanced diagnostics for atherosclerosis.
• Current IVUS/PA catheters often require separate transducers, leading to larger device sizes.
• Integrating multiple imaging modalities into a single, compact catheter is crucial for clinical application.

Purpose of the Study:

• To design and fabricate a dual-transducer acoustic stack for combined IVUS/PA imaging.
• To enable multimodal imaging within conventional intravascular catheter dimensions.
• To enhance diagnostic accuracy for cardiovascular diseases like atherosclerosis.

Main Methods:

• Developed a dual-transducer acoustic stack with a low-frequency (LF) PA receiver acting as a matching layer for a high-frequency (HF) US transducer.
• Simulated the acoustic performance of the integrated stack.
• Fabricated and experimentally validated the performance of the acoustic stacks using phantom experiments.

Main Results:

• The integrated acoustic stack design allows HF US transducers (50 MHz) and LF PA receivers (<15 MHz) to function within a compact form factor.
• Simulations predicted a 3.54 dB sensitivity increase for the HF transducer without compromising bandwidth.
• Phantom experiments confirmed enhanced sensitivity and bandwidth for the US transducer, validating the design's efficacy.

Conclusions:

• The proposed dual-transducer acoustic stack is a viable technology for compact, multimodal IVUS/PA imaging catheters.
• This innovation can significantly improve diagnostic accuracy for atherosclerosis.
• The design facilitates high-resolution, multifrequency imaging essential for comprehensive cardiovascular assessment.