Stable phantom materials for ultrasound and optical imaging

Area of Science:

• Biomedical Engineering
• Materials Science
• Medical Imaging

Background:

• Tissue-mimicking phantoms are crucial for medical device characterization.
• Current water-based phantoms suffer from degradation and poor temporal stability.
• Novel materials are needed for accurate ultrasound and optical imaging simulations.

Purpose of the Study:

• To develop and characterize a new oil-based phantom material for ultrasound and optical imaging.
• To evaluate the acoustic and optical properties of styrene-ethylene/butylene-styrene (SEBS) and low-density polyethylene (LDPE) blends.
• To assess the material's suitability for advanced imaging techniques like photoacoustic imaging.

Main Methods:

• Formulated oil-based phantoms using SEBS (5%-15%) and LDPE (0%-9%) in mineral oil.
• Measured acoustic properties (speed of sound, attenuation) from 1-10 MHz.
• Characterized optical properties (diffuse reflectance, transmittance) from 400-1200 nm, calculating scattering and absorption coefficients.
• Acquired ultrasound and photoacoustic images of a heterogeneous phantom with an annatto dye-enhanced inclusion.

Main Results:

• SEBS/LDPE phantoms exhibited acoustic properties consistent with soft tissues, tunable by varying component concentrations.
• SEBS gels showed low optical absorption and scattering, while LDPE increased turbidity, absorption, and scattering.
• Ultrasound and photoacoustic imaging demonstrated the phantom's capability to represent heterogeneous structures.

Conclusions:

• The developed oil-based SEBS/LDPE copolymer gels offer low temporal degradation, outperforming traditional water-based phantoms.
• These materials possess tunable acoustic and optical properties suitable for simulating biological tissues.
• The phantoms show significant potential for applications in ultrasound, optical, and photoacoustic imaging.