Fig. 3.
One-dimensional imaging results of the phantom. (a) Time-reversed direct current (TRDC) image acquired without ultrasound modulation. (b) Time-reversed ultrasonically encoded (TRUE) image acquired using single-transducer (T1) modulation. (c) TRUE image acquired using dual-transducer () modulation. The experimental data were fitted by the theoretic simulations (solid lines). The incident signal beam and the two ultrasonic transducers were stationary, while the phantom was scanned along the axis.