Low-cost microvascular phantom for photoacoustic imaging using loofah

Area of Science:

• Biomedical Engineering
• Optical Imaging
• Materials Science

Background:

• Existing photoacoustic phantoms lack the complex microvascular structures needed for accurate imaging.
• There is a need for versatile phantom materials that can replicate intricate vascular networks.

Purpose of the Study:

• To introduce loofah as a novel, natural phantom material for photoacoustic imaging.
• To fabricate phantoms with controlled optical properties mimicking human microvasculature using loofah.

Main Methods:

• Incorporated controllable chromophores into loofah to tailor absorption properties.
• Evaluated loofah phantom performance using co-registered ultrasound, acoustic-resolution photoacoustic microscopy (ARPAM), and optical-resolution photoacoustic microscopy (ORPAM).

Main Results:

• Optical-resolution photoacoustic microscopy confirmed controlled chromophore distribution and consistent photoacoustic signals.
• Acoustic-resolution photoacoustic microscopy demonstrated loofah phantoms effectively replicate vascular structures (100-500 µm diameter), outperforming conventional phantoms.
• Loofah phantoms exhibited stability in photoacoustic signal generation.

Conclusions:

• Loofah offers a low-cost, effective method for creating submillimeter microvascular phantoms for photoacoustic imaging.
• The material's morphology and customizability enable diverse vascular network configurations, improving phantom imaging fidelity.
• These realistic phantoms aid in system calibration, validation, and provide data for training machine learning models.