Reverberation reduction in ultrasonic B-mode images via dual frequency image subtraction.

The authors demonstrate the feasibility of an approach, dual-frequency subtraction imaging, for suppressing artifacts produced by reverberation of strong echoes among specular reflectors. This method is based upon the principle that specularly reflected echoes from flat boundaries are frequency-independent whereas the diffusely scattered echoes from small scatterers are frequency-dependent. The approach was assessed on phantoms including one consisting of two parallel plastic plates between layers of foam sponges using a prototype experimental system. Preliminary results show that this method is superior to simple thresholding techniques or signal compression and holds great promise for suppressing reverberation artifacts in ultrasonic images.