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

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.

Benign breast lesions: Ultrasound

“…Sonoelastography evaluates the different elastic properties of the tissues and is best applied in the evaluation of breast lesions, as there is a substantial difference between fibroglandular tissue and nodules of different types; malignant lesions are generally less elastic than benign masses [20,21]. A slight rhythmic compression is applied using the transducer positioned perpendicular to the breast, so that the relative deformation of the underlying tissues can be reconstructed and displayed on the monitor sometimes in black and white images; otherwise in color images which yield a better view of the degree of tissue elasticity.…”

Strain Elastography of Breast and Prostata Cancer: Similarities and Differences

“…For most mammary lesions, benign tumors are harder than normal glandular tissues, but softer than malignant lesions [25]. False-positive changes can be observed in hyaline fibroadenomas and fatty tissue necrosis, since these can involve tissue hardening [5, 26,27]. Additionally, USE has difficulty differentiating between postoperative scarring and tumor recurrence, since in both cases there is reduced tissue elasticity.…”

“…Since USE represents an additive to B-mode sonography, false-negative changes play a reduced role in the detection of breast cancer. Most false-negative changes are found, for example, in phyllodes tumors with a soft center, mucoid breast carcinomas and carcinomas with large central necrosis [5,17,26,27]. In a B-mode image, both entities are shown as suspicious.…”

Probing model tumor interfacial properties using piezoelectric cantilevers

“…[1][2][3] Potentially one can use elasticity measurement to detect breast tumor. However, the elastic modulus measurement is not adequate as benign breast tumors also exhibit a larger elastic modulus than the surrounding normal tissue.…”

“…However, the elastic modulus measurement is not adequate as benign breast tumors also exhibit a larger elastic modulus than the surrounding normal tissue. 2 Measuring tissue elastic modulus alone would not differentiate breast cancers from benign tumors. Anecdotal physicians' experience indicates that malignant tumors are less mobile than benign tumors.…”