Separation of mainlobe and sidelobe contributions to B-mode ultrasound images based on the aperture spectrum

Abstract

Isolating the mainlobe and sidelobe contribution to an ultrasound image can improve imaging contrast by removing sidelobe clutter. Previous work achieves the separation of mainlobe and sidelobe contributions based on the covariance of received signals. However, formation of a covariance matrix of receive signals at each imaging point can be computationally burdensome and memory intensive for real-time applications. This work demonstrates that the mainlobe and sidelobe contribution to the ultrasound image can be isolated based on the receive aperture spectrum, which greatly reduces computational and memory requirements. This aperture spectrumbased approach is shown to improve lesion contrast by16.5-41.2 dB beyond conventional delay-and-sum B-mode imaging, while the prior method based on the covariance model achieves 6.1 to 21.9 dB contrast improvement beyond conventional delay-and-sum.