Elastic moduli of normal and pathological human breast tissues: an inversion-technique-based investigation of 169 samples

TLDR

The mechanical properties of breast tissues are crucial for surgical planning, virtual‑reality training, and elastography diagnostics, yet reliable, consistent data are scarce. We developed specialized ex vivo elasticity measurement techniques and applied them to 169 fresh breast tissue samples, encompassing normal fat, fibroglandular tissue, and a spectrum of benign and malignant tumors. Normal fat and fibroglandular tissues had similar moduli, fibroadenomas were about twice as stiff, while fibrocystic disease and malignant tumors showed 3–6‑fold increases, with high‑grade invasive ductal carcinoma reaching up to 13‑fold, all differences being statistically significant and highlighting elastography’s diagnostic specificity.

Abstract

Understanding and quantifying the mechanical properties of breast tissues has been a subject of interest for the past two decades. This has been motivated in part by interest in modelling soft tissue response for surgery planning and virtual-reality-based surgical training. Interpreting elastography images for diagnostic purposes also requires a sound understanding of normal and pathological tissue mechanical properties. Reliable data on tissue elastic properties are very limited and those which are available tend to be inconsistent, in part as a result of measurement methodology. We have developed specialized techniques to measure tissue elasticity of breast normal tissues and tumour specimens and applied them to 169 fresh ex vivo breast tissue samples including fat and fibroglandular tissue as well as a range of benign and malignant breast tumour types. Results show that, under small deformation conditions, the elastic modulus of normal breast fat and fibroglandular tissues are similar while fibroadenomas were approximately twice the stiffness. Fibrocystic disease and malignant tumours exhibited a 3–6-fold increased stiffness with high-grade invasive ductal carcinoma exhibiting up to a 13-fold increase in stiffness compared to fibrogalndular tissue. A statistical analysis showed that differences between the elastic modulus of the majority of those tissues were statistically significant. Implications for the specificity advantages of elastography are reviewed.