Evaluation of transmit/receive apodization scheme for hardware implementation used in B-mode ultrasound imaging

摘要

For B-mode phased array ultrasound imaging, Sidelobes are skirts of ultrasound waves around the main lobe. Sidelobes degrade image quality by decreasing Signal to Noise Ratio (SNR), Contrast Ratio (CR) and spatial resolution. By using an apodization function that applies different amplifications to the transmitted and received signals we can increase the width of the main lobe and reduce the level of the sidelobes. In this paper, we evaluate the tradeoffs between performance metrics and computational cost for ten windowing functions. Performance evaluation is based on the image quality metrics for Point Spread Function (PSF) and Cyst Phantom (CP) simulations by measuring the spatial resolution, CR, Contrast to Noise Ratio (CNR) and the Signal to Noise Ratio (SNR) metrics for each window function output image. On the other hand, we estimate the computational cost by measuring the FLOPS (Floating Points Operations per Second). B-mode simulations prove that Flattop/Nuttall couple gives the highest CNR value in comparison with the other couples for the optimum computation cost.