REVERBERATION REDUCTION IN ULTRASONIC B-MODE IMAGES VIA DUAL-FREQUENCY IMAGE SUBTRACTION

The aim of this paper is to demonstrate the feasibility of an approach : dual-frequency subtraction imaging, for suppressing artifacts produc ed by reverberation of strong echoes among specular reflectors. This m ethod is based upon the principle that specularly reflected echoes fro m fiat boundaries are frequency-independent whereas the diffusely scat tered echoes from small scatterers are frequency-dependent. The approa ch was assessed on phantoms including one consisting of two parallel p lastic plates between layers of foam sponges using a prototype experim ental 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.