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Enhanced visibility through microbubble-induced photoacoustic fluctuation imaging
Marco A Inzunza-Ibarra1, J Angel Navarro-Becerra1, Venkatalakshmi Narumanchi2
1Department of Mechanical Engineering, University of Colorado, Boulder, Colorado 80309, USA.
JASA Express Letters
|January 10, 2022
Summary
This study introduces a new photoacoustic contrast method using microbubbles to enhance imaging of blood flow. Increased microbubble concentration and size non-linearly boost photoacoustic signal fluctuations, improving contrast and visibility in blood flow phantoms.
Area of Science:
- Biomedical Optics
- Acoustic Imaging
- Microfluidics
Background:
- Photoacoustic imaging (PAI) offers functional and structural information.
- Enhancing contrast in PAI, especially for microvasculature, remains a challenge.
- Microbubbles are established contrast agents but their application in PAI fluctuations is less explored.
Purpose of the Study:
- To develop and validate a novel photoacoustic contrast mechanism utilizing microbubble-induced fluctuations.
- To investigate the relationship between microbubble properties and photoacoustic signal variations.
- To demonstrate improved imaging of blood flow using this fluctuation-based contrast method.
Main Methods:
- A photoacoustic setup was used to measure signals from a micro-vessel phantom.
- Microbubbles of varying concentrations and sizes were introduced into a continuous absorber.
- The standard deviation of photoacoustic signals was analyzed as a function of microbubble parameters.
Main Results:
- A non-linear increase in the standard deviation of photoacoustic signals was observed with increasing microbubble concentration and size.
- This signal fluctuation effect was directly correlated with microbubble presence and characteristics.
- Photoacoustic fluctuation imaging demonstrated significantly enhanced visibility and contrast of the blood flow phantom.
Conclusions:
- Microbubble-induced photoacoustic fluctuations provide a viable contrast enhancement mechanism.
- The developed method offers a promising approach for high-contrast microvascular imaging.
- This technique has potential applications in diagnosing and monitoring conditions related to blood flow.
