Biopathologic Characterization and Grade Assessment of Breast Cancer With 3-D Multiparametric Ultrasound Combining Shear Wave Elastography and Backscatter Tensor Imaging

Abstract

ObjectiveDespite recent improvements in medical imaging, the final diagnosis and biopathological characterization of breast cancers currently still requires biopsies. Ultrasound is commonly used for clinical examination of breast masses. B-mode and Shear Wave Elastography (SWE) are already widely used to detect suspicious masses and differentiate benign lesions from cancers. But additional ultrasound modalities such as Backscatter Tensor Imaging (BTI) could provide relevant biomarkers related to tissue organization. Here we present a 3D multiparametric ultrasound approach applied to breast carcinomas aiming to (i) validate the ability of BTI to reveal the underlying organization of collagen fibers and (ii) assess the complementarity of SWE and BTI to reveal biopathological features of diagnostic interest. Methods3D SWE and BTI were performed ex vivo on 64 human breast carcinoma samples using a linear ultrasound probe moved by a set of motors. In this paper, we present a 3D multiparametric representation of the breast masses and quantitative measurements combining B-mode, SWE and BTI. ResultsOur results show for the first time that BTI can capture the orientation of the collagen fibers around tumors. BTI was found to be a relevant marker for assessing cancer stages revealing a more tangent tissue orientation for in situ carcinomas than for invasive cancers. In invasive cases, the combination of BTI and SWE parameters allowed for classification of invasive tumors with respect to their grade with an accuracy of 95.7%. ConclusionOur results highlight the potential of 3D multiparametric ultrasound imaging for biopathological characterization of breast tumors.