Improvement Of Range Resolution Of Fdmas Beamforming In Ultrasound Imaging

Ultrasound imaging is applied to various fields because it is noninvasive and real-time imaging is possible. However, in diagnosis applications, ultrasound imaging is inferior in resolution to other modalities, so researches for improving resolution have been actively conducted. Recently, researches on beamforming methods have been advanced for the purpose of improving lateral resolution. In order to form a narrower beam, adaptive beamformers such as the MV (minimum variance) beamformer that adaptively changes the beamforming weights have been proposed, but these methods increase the computational complexity. Therefore, in recent years, the FDMAS (Filtered-Delay Multiply And Sum) beamformer which can realize high resolution and high contrast without using complicated calculation attracts attention. On the other hand, we proposed a method called the SCM (Super resolution FM-Chirp correlation Method) that improves range resolution based on frequency sweep. In addition, we proposed a new DAS (Delay And Sum) beam former which improves range resolution by multiplying the echo signal by the result of the SCM before DAS processing. This method is constructed in the usual RF (Radio Frequency) band. In this study, we first reconstruct the FDMAS as a base-band processing in order to improve the SNR, and apply the SCM result to the FDMAS in order to improve both range and lateral resolution.