Breast tumor classification using axial shear strain elastography: a feasibility study

Abstract

Recently, the feasibility of visualizing the characteristics of bonding at an inclusion-background boundary using axial-shear strain elastography was demonstrated. In this paper, we report a feasibility study on the utility of the axial-shear strain elastograms in the classification of in vivo breast tumor as being benign or malignant. The study was performed using data sets obtained from 15 benign and 15 malignant cases that were biopsy proven. A total of three independent observers were trained, and their services were utilized for the study. A total of 9 cases were used as training set and the remaining cases were used as testing set. The feature from the axial-shear strain elastogram, namely, the area of the axial-shear region, was extracted by the observers. The observers also outlined the tumor area on the corresponding sonogram, which was used to normalize the area of the axial-shear strain region. There are several observations that can be drawn from the results. First, the result indicates that the observers consistently ( approximately 82% of the cases) noticed the characteristic pattern of the axial-shear strain distribution data as predicted in the previous simulation studies, i.e. alternating regions of positive and negative axial-shear strain values around the tumor-background interface. Second, the analysis of the result suggests that in approximately 57% of the cases in which the observers did not visualize tumor in the sonogram, the elastograms helped them to locate the tumor. Finally, the analysis of the result suggests that for the discriminant feature value of 0.46, the number of unnecessary biopsies could be reduced by 56.3% without compromising on sensitivity and on negative predictive value (NPV). Based on the results in this study, feature values greater than 0.75 appear to be indicative of malignancy, while values less than 0.46 to be indicative of benignity. Feature values between 0.46 and 0.75 may result in an overlap between benign and malignant cases.

Axial–Shear Strain Distributions in an Elliptical Inclusion Model: Experimental Validation and in vivo Examples With Implications to Breast Tumor Classification

“…Recently, we have demonstrated that axial-shear strain elastography may aid in breast tumor classification by adding independent tissue mechanics information pertaining to the bonding of a tumor to its surrounding (ThitaiKumar et al 2007(ThitaiKumar et al , 2008. The underlying hypothesis for the previously reported work was based on the characteristic differences in the mobility of benign and malignant lesions noted in the literature.…”

The value of ultrasound elastography in differential diagnosis of superficial lymph nodes

“…It can display the texture of the tissue and reflect the biological characteristics of the mass [4]. It shows promising prospects in differentiating benign from malignant breast tumor [5][6][7][8][9][10][11]. The semi-quantitative sonoelastography makes the elasticity evaluation more easily [12].…”

Use of shear wave elastography to differentiate benign and malignant breast lesions

“…Although the total number of females referred for interventional diagnostic procedures represents a small percentage of any screened population, the healthcare resources consumed by such females are disproportionately high (11). Further, the pathological result is benign in up to 75% of all cases (11)(12)(13). Therefore, a reliable, noninvasive, costeffective method helping to differentiate benign from malignant breast lesions, thus reducing the number of unnecessary interventional diagnostic procedures, would be valuable.…”