Focused Ultrasound Steering for Harmonic Motion Imaging

Harmonic motion imaging (HMI) is a radiation-force-based ultrasound elasticity imaging technique, which is designed for both tissue relative stiffness imaging and reliable high-intensity focused ultrasound treatment monitoring. The objective of this letter is to develop and demonstrate the feasibility of 2-D focused ultrasound (FUS) beam steering for HMI using a 93-element, FUS phased array. HMI with steered FUS beam was acquired in tissue-mimicking phantoms. The HMI displacement was imaged within the steering range of +/- 1.7 mm laterally and +/- 2 mm axially. Using the steered FUS beam, HMI can be used to image a larger tissue volume with higher efficiency and without requiring mechanical movement of the transducer.