Stabilization techniques for high resolution ultrasound imaging using beamspace Capon method

Several adaptive beamforming imagers have been proposed to improve the spatial resolution of medical ultrasound imaging. These imagers employ spatial averaging technique and diagonal loading technique to suppress correlated interferences and to acquire robustness, respectively. In this study, we propose the technique that selects the optimum size for spatial averaging with respect to the measurement depth. We employ a small diagonal loading factor of -40 dB to avoid the deterioration in image quality. In a simulation study, the proposed method succeeded to improve the image quality compared to a conventional beamspace Capon method. The sidelobe level and the -6 dB beam width in the proposed method were -26 dB and 0.27 mm, respectively, where those in the conventional method were -16 dB and 0.40 mm, respectively. The proposed method succeeded to depict the higher resolution image than that of the conventional method.