A Novel Method for Ultrasound Attenuation Imaging Based on Mechanical Reciprocity and Acoustic Radiation Force

We demonstrate a novel method employing the principle of mechanical reciprocity to image the relative ultrasound attenuation. In this approach, which we call shearwave reciprocity imaging (SRI), acoustic radiation force is used to push on the medium at one location while displacement is tracked at a second location. The push and track locations are then transposed. Differences in the measured displacements reveal differences in acoustic radiation force due to differences in attenuation. In contrast to shear wave elastography, the use of mechanical reciprocity ensures that this approach provides attenuation images independent of tissue elasticity. Imaging was performed with a Verasonics Vantage 64 LE system and ATL L7-4 linear array on tissue-mimicking phantoms of gelatin and Zerdine containing lesions of enhanced attenuation. We demonstrate imaging of the increased attenuation of the inclusions relative to background, independent of their elastic modulus. These attenuation measurements are complimentary to elastogram and B-mode data and provide an additional source of image contrast for lesion characterization.