Phantom materials for elastography

TLDR

The study reports acoustic and mechanical properties of gelatin phantoms designed for elastography. The authors developed a measurement device and protocol to assess elastic properties, stress relaxation, temporal stability, melting point, and stiffness tuning via aldehyde‑induced cross‑linking in gelatin phantoms. Compression forces matched finite element predictions, the phantoms spanned a wide range of tissue‑like elasticities, but gels stiffened over weeks, with elastic modulus precision from <0.1 % at 100 kPa to 8.9 % for soft (<10 kPa) samples.

Abstract

Acoustic and mechanical properties are reported for gelatin materials used to construct tissue-like phantoms for elasticity imaging (elastography). A device and procedure for measuring elastic properties are described. The measured compression forces were comparable to results obtained from finite element analysis when linear elastic media are assumed. Also measured were the stress relaxation, temporal stability, and melting point of the materials. Aldehyde concentration was used to increase the stiffness of the gelatin by controlling the amount of collagen cross-linking. A broad range of tissue-like elastic properties was achieved with these materials, although gels continued to stiffen for several weeks. The precision for elastic modulus measurements ranged from less than 0.1% for 100 kPa samples to 8.9% for soft (<10 kPa), sticky samples.