engleski

Elastic Modulus of Malignant Breast Lesions with Shear Wave Elastography: Variations with Different Region of Interest Size

Ultrasound elastography is a newly developed ultrasound technology which detects malignant breast lesions by measuring the changes in stiffness of breast tissues. The two principal types of ultrasound elastography are strain and shear wave elastography (SWE). Strain elastography is performed by manual compression using a transducer which produces an image based on the resulting displacement of the breast tissues. However, it is difficult to standardize and quantify the force applied during compression, thus, absolute elasticity values cannot be calculated, only qualitative results can be obtained. On the other hand, SWE is a type of ultrasound elastography by which breast tissue stiffness can be assessed both qualitatively and quantitatively using elastic modulus values. The elastic modulus values are obtained by producing a focused ultrasound beam which induces mechanical vibrations via an acoustic radiation force. The induced displacement produces shear waves which are detected by the ultrasound probe and the elastic properties of tissues are displayed qualitatively, colour-coded and superimposed on the B-mode image in real-time. Elasticity information can also be expressed quantitatively via elastic modulus Emean, Emax and Emin values, measured in the units of kilopascal (kPa). The values are obtained by placing a region of interest (ROI) circle over the target tissue in the SWE acquisition box after the elastic values of the tissues were obtained during a breast ultrasound examination. Several clinical studies were published on the topic of the use of SWE in diagnosing malignant breast diseases, however, only few of them addressed the ROI size and its effects on the measured values. Therefore, the purpose of this study was to determine whether a change in size of the ROI area on SWE causes a statistically significant difference in the measured values of the mean, maximum and minimum elastic modulus values of malignant breast lesions.

ultrasound ; breast lesions, elastography

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