Acoustic characterisation of a modified IEC agar-based tissue-mimicking material across the 3.5–50 MHz frequency range

The IEC agar-based tissue-mimicking material (TMM) is widely used in the manufacture of ultrasound phantoms. Whilst the impact of freezing on the structural properties of the material is well-known, its impact on the acoustic properties of the TMM remains uncharacterised. PVA cryogel is another popular TMM for ultrasound, but requires cross-linking through freeze-thaw cycles to achieve the required acoustic properties.
The aim of this study was therefore to quantify the impact of freeze-thaw cycles on the IEC agar-based TMM to assess the feasibility of multi-material ultrasound phantoms combining both TMMs.
No significant variations in acoustic attenuation could be observed with increasing freeze-thaw cycles, however significant changes in the speed of sound as well as the presence of cracks could be observed.

All data related to acoustic characterisation was gathered using a scanning acoustic macroscope across the 3.5-50MHz range.