Fig. 2.

ARFI pulse sequence consisting of an ensemble of reference pulse(s), pushing pulse(s), and tracking pulse(s) applied at each of multiple lateral locations uniformly distributed across the FOV. In the first portion of the sequence, 4 MHz pulse inverted (+ and −) pulses were used to construct 1) 4 MHz fundamental 2) filtered harmonic and 3) pulse inversion harmonic images. In the second portion of the sequence, identical polarity (+) 8 MHz pulses were used to construct an 8 MHz fundamental image.