The application of k-space in pulse echo ultrasound

K-space is a frequency domain description of imaging systems and targets that can be used to gain insight into image formation. Although originally proposed in ultrasound for the analysis of experiments involving anisotropic scattering and for the design of acoustic tomography systems, it is particularly useful for the analysis of pulse echo ultrasonic imaging systems. This paper presents analytical and conceptual techniques for estimating the k-space representation of pulse echo imaging systems with arbitrary transmit and receive array geometries and apodizations. Simple graphical methods of estimating the first and second order statistics of speckle are presented. Examples are presented that utilize k-space to gain insight regarding the performance of spatial and frequency compounding and to describe the impact of synthetic receive aperture geometry on beamforming and speckle statistics. The Van Cittert-Zernike theorem is presented in k-space, and techniques for improving echo coherence are discussed.