Monitoring of lesions induced by cavitation-enhanced high-intensity focused ultrasound using shear wave elastography

Shear wave elastography is expected as a noninvasive monitoring method in high-intensity focused ultrasound treatment. Since elastography is usually applied to detect a lesion near a superficial layer, it is challenging to induce and propagate shear waves in deep tissue. Acoustic cavitation bubbles have the potential to promote the efficiency of the treatment; however the presence of remaining microbubbles may interfere with the shear wave propagation and make the detection of the accompanying displacements difficult. In this paper, it is examined whether the detection of the region where increased shear wave propagation velocity in ex vivo tissue is possible even in the presence of microbubbles and “HIFU push” shear wave elastography has the advantage in terms of shear wave induction in deep tissue compared with a conventional technique by irradiating push beams from the same therapeutic transducer as HIFU exposure.