A post-beamforming processing technique for enhancing conventional pulse-ultrasound imaging contrast resolution

An object-dependent post-beamforming processing (PBP) technique is presented for improving conventional ultrasound imaging contrast resolution (CR). The technique is derived from the conventional delay-and-sum beamforming (DSB) algorithm and contains two major procedures. First, it utilizes the DSB results as an estimate of the actual image. Second, each estimated image pixel is processed by an object-dependent weighting factor for further suppressing sidelobe energy. Experimental results based on phantom data show that, with this technique, the sidelobe energy resulting from DSB can be significantly reduced. The system CR is thus improved. This CR improvement has also been quantitatively verified by image contrast to noise ratio (CNR) measurements. The algorithm can be implemented in real-time by adding a processing unit to the current conventional imaging system.