Beamforming methods in the field of medical ultrasonics

Abstract

Delay-and-sum (DAS) beamforming is widely used to generate B-mode images using the echo signals obtained from transducer elements of ultrasound array probes. However, the spatial resolution and contrast provided by DAS beamforming are limited by the physical specifications of the array such as element spacing. To overcome such constraints, adaptive beamforming techniques have been actively researched and developed, particularly with the proliferation of digital and programmable ultrasound systems in recent years. On the other hand, it is also important to quantitatively evaluate whether the methods developed improve the characteristics of images. Recently, many adaptive beamforming techniques, which often alter the characteristics of ultrasound images, have been developed. Therefore, efforts have been made to improve quantitative methods for assessing image quality. In this article, we primarily review recent developments in adaptive beamforming and image quality evaluation methods.