Anisotropy of Solid Breast Lesions in 2D Shear Wave Elastography is an Indicator of Malignancy

Abstract

Rationale and Objectives: To investigate if anisotropy at 2D Shear Wave Elastography (SWE) suggests malignancy and whether it correlates with prognostic and predictive factors in breast cancer. Materials and Methods: Study-group A of 244 solid breast lesions was imaged with SWE between April 2013 and May 2014. Each lesion was imaged in radial and anti-radial planes and the maximum elasticity Emax, mean elasticity Emean and standard deviation SD were recorded and correlated with benign/malignant status and if malignant, to conventional predictive and prognostic factors. The results were compared to a study-group B of 968 solid breast lesions, which were imaged in sagittal and axial plane between 2010 and 2013.

Shear-wave elastography in breast ultrasonography: the state of the art

“…However, ROI size should be considered when interpreting the results of E mean . Because E mean is the sum of all elasticity values of each pixel within the ROI divided by the number of pixels, its absolute value depends on the size of the ROI; that is, a higher E mean value for a smaller ROI is expected [ 28 ]. E SD , representing the average difference in elasticity value within the ROI to E mean , is also influenced by the ROI size [ 28 ].…”

“…Because E mean is the sum of all elasticity values of each pixel within the ROI divided by the number of pixels, its absolute value depends on the size of the ROI; that is, a higher E mean value for a smaller ROI is expected [ 28 ]. E SD , representing the average difference in elasticity value within the ROI to E mean , is also influenced by the ROI size [ 28 ]. As the size of the ROI changes, the sampling of the elasticity information becomes more variable, meaning that elastic heterogeneity will increase or decrease, particularly in a heterogeneous malignant lesion.…”

“…For E ratio , the optimal measurement of reference fat elasticity is crucial, as fat elasticity is the denominator in calculating E ratio , and even a small difference in fat elasticity can cause a large difference in E ratio [ 8 ]. In addition, SWE anisotropy-the difference in lesion elasticity measured in two orthogonal planes could be used in the diagnosis of breast lesions [ 28 ]. Malignant lesions are more anisotropic than benign lesions.…”

Lipotransfer for radiation-induced skin fibrosis

“…Qualitative information is also provided via the generation of a tissue stiffness map. USWE has been shown to be useful for assessing liver fibrosis, and predicting malignancy risk in thyroid nodules or discrete breast lesions. Sowa et al .…”

Ultrasound shear wave elastography of breast lesions: correlation of anisotropy with clinical and histopathological findings

“…Recently, Zhou et al has demonstrated the anisotropy of elasticity of normal breast glandular and fatty tissue by comparing measurements of radial and antiradial planes [ 13 ]. Previous studies observed anisotropy in solid breast lesions [ 14 ], and Skerl et al discovered anisotropy in SWE as an indicator of malignancy [ 15 ]. Nevertheless, in the aforementioned study, the anisotropy factor (AF) was calculated with Emean, which was defined as mean elasticity of the stiffest area using a region of interest size (ROI) of 2 mm, rather than the measurements of the whole lesions.…”