Enhanced tagging of light utilizing acoustic radiation force with speckle pattern analysis

Area of Science:

• Biomedical optics
• Acoustic imaging
• Hybrid imaging modalities

Background:

• Optical imaging depth and resolution are limited by light scattering in tissues.
• Ultrasound (US) waves exhibit negligible scattering, offering an advantage for deep tissue imaging.
• Hybrid imaging combines modalities to leverage their respective strengths.

Purpose of the Study:

• To investigate the use of acoustic radiation force (ARF) to enhance ultrasound-modulated optical tomography (UOT).
• To model and simulate US insonation processes for hybrid imaging.
• To analyze the signal strength and information content of ARF-tagged light compared to traditional UOT.

Main Methods:

• Developed a simulation model for US insonation processes.
• Utilized fixed-particle Monte Carlo simulations.
• Performed experimental validation.
• Analyzed mean irradiance change (MIC) signals to assess thermal and mechanical effects.

Main Results:

• ARF-induced phase changes result in stronger optical signals compared to conventional UOT.
• The MIC signal effectively captures both thermal and mechanical effects of focused US beams.
• Simulation and experimental results confirm the superiority of ARF-based signal acquisition.

Conclusions:

• ARF significantly enhances signal detection in hybrid optical-ultrasound imaging.
• The MIC signal provides insights into US-tissue interactions on various timescales.
• ARF-based methods show potential for generating displacement images for improved biomedical imaging.