Poly(vinyl alcohol) gel ultrasound phantom with durability and visibility of internal flow

Purpose: Among various existing flow phantoms, none is characterized by appropriate acoustic, visibility, and durability properties simultaneously. The aim of this study was to develop a durable ultrasound phantom with visibility of the internal flow.

Methods: Poly(vinyl alcohol) (PVA) gel was chosen as the basic material. The acoustic properties of various PVA gels were measured with 40-MHz ultrasound, the compositions of PVA, dimethyl sulfoxide (DMSO), and glass microbeads being changed, while visually checking the transparency. Wall-less ultrasound flow phantoms with a straight channel 2 mm in diameter were made from PVA gel, and ultrasound B-mode imaging was conducted with blood-mimicking fluid flow.

Results: The acoustic properties of in vivo soft tissue were reproduced by PVA gel with a PVA concentration of 15 mass% and a glass microbead concentration of 2.9 mass% in a solvent of 98 mol% DMSO, showing acoustic properties of 1567 ± 4 m/s and 56 ± 5 dB/cm. The PVA gel was durable with visibility of the flow in the ultrasound phantom. The ultrasound B-mode image of the ultrasound flow phantom showed features approximating those of a mouse carotid artery.

Conclusion: A durable PVA gel ultrasound phantom with visibility of the internal flow was developed.