Characterization of tissue-mimicking polyvinyl alcohol phantoms for shear wave viscoelastography: effects of aluminum oxide and cryoprotectant concentration
Devyani Gupta, Akash Chandra, Jagruti M. Patil, Karla P. Mercado-Shekhar
Polyvinyl alcohol (PVA) phantoms are used to evaluate shear wave elastography and viscoelastography systems. This study investigated how aluminum oxide and the cryoprotectants ethylene glycol (EG) and propylene glycol (PG) affect the microstructural, acoustic, and viscoelastic properties of PVA phantoms. Phantoms containing 10% PVA were fabricated with varying concentrations of aluminum oxide, EG, or PG. Their microstructure, density, longitudinal sound speed, acoustic attenuation, shear modulus, and viscosity were evaluated. Aluminum oxide increased acoustic attenuation, density, and shear modulus, while its effects on longitudinal sound speed and viscosity were not statistically significant. Increasing EG and PG concentrations increased sound speed and influenced attenuation. Their effects on shear modulus and viscosity were concentration-dependent and nonlinear. These findings demonstrate that additives can simultaneously alter several phantom properties, highlighting the importance of carefully controlling formulation parameters to improve the standardization, accuracy, and reproducibility of ultrasound elastography experiments.