Advanced synthetic aperture technique to enhance image quality in ultrasound elastography: A novel strategy

Quasi-static elastography (QSE) is a well-established technique used in medical imaging, where ultrasound data is collected both, before and after applying a slight compression on a tissue. This data is then analyzed to create image frames that reveal the stiffness parameter of the underlying tissue medium. Previous studies have focused on assessing how the Conventional Focused Beam (CFB) transmit method impacts the ultrasound elastography image quality. Recent studies have also shown an interest in synthetic aperture techniques like the Diverging Beam Synthetic Aperture Technique (DBSAT), due to its potential to enhance ultrasound image quality. However, its application in elastography has received limited attention. This paper introduces a new strategy of averaging low-resolution elastogram frames (LREA), obtained from DBSAT transmit method to improve the quality of elastography images. The CFB technique involves scanning the tissue line by line. In contrast, DBSAT is a synthetic aperture method that generates multiple low-resolution elastogram frames before combining them together to create a single high-quality image. In this research paper all the experimental studies were conducted on an agar-gelatin phantom, demonstrating the effectiveness of estimating elastograms from the low-resolution frame data of DBSAT transmit scheme and then summing them together to produce an elastogram with enhanced image quality. The results show a maximum improvement of 8 dB in the image quality metric of signal-to-noise ratio (SNR) as well as a 7 dB improvement in contrast-to-noise ratio (CNR) when comparing elastography images obtained by the proposed LREA method and the elastography images obtained by regular processing of the RF data acquired using the different methods of CFB and DBSAT.