Combination of Shear Wave and Strain Elastography

There is a trend for systems to offer both strain elastography (SE) and shear wave elastography (SWE) for breast elastography evaluation. The advantages and disadvantages of SE and SWE are complementary. ▶ Table 5.1 summarizes the advantages and disadvantages of the two complementary techniques. There may be situations where one technique will provide accurate results, whereas the other has limitations. For example, an adequate shear wave may not be measured in deep lesion due to attenuation of the ARFI pulse, however an adequate SE can be obtained. In cases where a benign lesion is adjacent to glandular tissue and the stain values are similar for both SE may be difficult to interpret where the quantitative nature of SWE will provide accurate results. Having the appropriate elastographic tool for a given patient may increase the accuracy of elastography in characterization of breast lesions.

**Table 5.1** Comparison of the properties of strain and shear wave elastography
Property	Strain elastography	Shear wave elastography
Imaging at depth	++++	+
Effect of precompression	+++	+++
Sensitivity (Is a lesion malignant?)	++++	++
Specificity (Is a lesion benign?)	++	++++
Quantitative	+	++++
Cyst characterization	++++	++