Evaluation of physical properties and image quality of a breast tissue phantom with glycerol-enhanced polyvinyl chloride plastisol for ultrasound imaging.

Abstract

Purpose: This study aimed to fabricate and evaluate breast tissue-equivalent phantoms with varying glycerol concentrations, focusing on their physical properties (density, elasticity, and acoustic parameters) and ultrasound image quality metrics, including echogenicity and lesion geometric accuracy.

Methods: Four phantom types were fabricated, each consisting of a polyvinyl chloride: dioctyl phthalate: glycerol mixture at varying ratios: 7%:93%:0% (background phantom A); 7%:88%:5% (background phantom B); 7%:83%:10% (background phantom C); and 7%:78%:15% (background phantom D). The phantoms contained spherical lesions (0.85, 1.10, and 1.45 cm) composed of gypsum, silicone rubber, and graphite. Physical properties such as density, elasticity, speed of sound, and acoustic impedance were measured for each phantom. Ultrasound image quality was assessed using signal-to-noise ratio, contrast-to-noise ratio, and geometric accuracy metrics.

Results: Background phantoms with higher glycerol concentrations demonstrated increases in density (1.012 to 1.073 g/cm3), elasticity (6.340 to 10.458 kPa), speed of sound (1,532.68±16.35 to 1,578.28±15.63 m/s), and acoustic impedance ([1.55±0.030 to 1.69±0.014]×106 kg/m2/s). Lesion size variation was less than 6.43%, indicating high geometric accuracy. Phantoms B, C, and D exhibited better echogenicity and clearer image contrast compared to phantom A, which showed an anechoic pattern.

Conclusion: Background phantom B demonstrated equivalence to breast tissue, and adding a specific concentration of glycerol allowed the mimicry of acoustic properties of target tissues, thereby improving image quality. This phantom can enhance ultrasound diagnostic skills and provides a cost-effective, self-build option suitable for medical training.