Transmit Delay and Standard Deviation Beamforming to Enhance Specular Reflections in Synthetic Transmit Aperture Imaging

Various methods have been proposed to replace X-ray by ultrasonic guidance in interventional operation. However, the presence of diffused speckle background may still hinder the needle detection. In this study, a combination of synthetic transmit aperture imaging (STA) and transmit delay and standard deviation beamforming (Tx-DASD) is developed. STA can provide higher resolution and better visualization of specular reflectors such as needles than conventional beam-by-beam counterpart. Tx-DASD can enhance the image contrast of ultrasound-guided needle biopsy by suppressing the diffused scattering. Furthermore, according to the properties of STA, we adjust the channel data by dropping extreme values to reduce the side-lobe artifacts in STA needle detection. Finally, we combine Tx-DASD with STA to enhance its usability.