Photoacoustic-Strain (PAS) Imaging for Tissue Microcirculation Assessment.

Area of Science:

• Biomedical Engineering
• Medical Imaging
• Physiology

Background:

• Microcirculation is vital for tissue health, facilitating nutrient and gas exchange.
• Dysfunction in microcirculation is linked to various systemic diseases.
• Current methods for assessing microcirculation can be invasive or lack spatial resolution.

Purpose of the Study:

• To introduce and validate photoacoustic-strain (PAS) imaging as a novel non-invasive method for assessing tissue microcirculation.
• To demonstrate the capability of PAS imaging in real-time monitoring of blood volume changes and microcirculatory dynamics.
• To establish PAS imaging as a robust tool for detecting microcirculatory alterations.

Main Methods:

• Development of photoacoustic-strain (PAS) imaging by combining ultrasound/photoacoustic imaging with external tissue deformation.
• Real-time monitoring of blood volume changes during applied pressure and subsequent release.
• Post-processing algorithms to reconstruct spatially resolved maps of blood displacement and reperfusion rates.
• In silico and in vivo validation of PAS imaging performance.

Main Results:

• PAS imaging successfully monitored blood displacement and refilling dynamics in microcirculation.
• Reconstructed maps provided insights into microcirculatory flow and reperfusion rates.
• The technique demonstrated high sensitivity and robustness in detecting microcirculatory changes.
• PAS imaging differentiated microcirculatory status under conditions like vascular occlusion and varying tissue temperatures.

Conclusions:

• Photoacoustic-strain (PAS) imaging is a validated, non-invasive tool for evaluating tissue microcirculation.
• PAS imaging offers real-time insights into microcirculatory function and dynamics.
• This technology holds significant potential for understanding and diagnosing diseases related to microcirculatory impairment.