Reusable ultrasonic tissue mimicking hydrogels containing nonionic surface-active agents for visualizing thermal...

Area of Science:

• Biomedical Engineering
• Materials Science
• Acoustic Imaging

Background:

• Therapeutic ultrasound applications rely on thermal mechanisms.
• Visualizing thermal lesions is crucial for quality assurance.
• Existing phantoms lack effective optical visualization of thermal lesions.

Purpose of the Study:

• To develop a novel, reusable tissue-mimicking phantom for optical visualization of thermal lesions.
• To control lesion formation temperature using temperature-sensitive indicators.
• To assess the phantom's suitability for therapeutic ultrasound applications.

Main Methods:

• Fabrication of polyacrylamide hydrogel phantoms incorporating nonionic surface-active agents (NiSAAs).
• Selection of NiSAAs with specific clouding points (66°C, 70°C, 80°C).
• Characterization of acoustic properties and optical transparency changes with temperature.

Main Results:

• NiSAA hydrogels exhibited acoustic properties similar to human liver.
• Phantoms transitioned from transparent to opaque above clouding points, enabling lesion visualization.
• Hysteresis was observed during transparency recovery upon cooling.

Conclusions:

• The developed NiSAA polyacrylamide hydrogel phantom allows optical visualization of thermal lesions.
• The phantom's properties are suitable for quality assurance in therapeutic ultrasound.
• This phantom offers a practical tool for applications where thermal mechanisms are critical.