New synthetic aperture imaging technique with dynamic apodization window

Abstract

Synthetic aperture (SA) imaging techniques can enhance spatial resolution in medical ultrasound imaging. However, it suffers from the degradation of image quality close to a virtual source (e.g., transmit focal point) since there is no enough transmit acoustic field energy. In this paper, a new SA imaging technique (i.e., dynamic synthetic aperture, DSA) where the number of synthetic scanlines for acoustic field superposition is dynamically adjusted based on the transmit acoustic field analysis. For the DSA technique, the dynamic apodization window function was generated from the Field II simulation and applied in the phantom and in vivo experiments. The raw radio-frequency (RF) data for phantom and in vivo experiments were captured by an Ultrasonix's SonixTouch research platform connected with a SonixDAQ parallel acquisition system. From the phantom experiment, the proposed DSA method shows the enhanced spatial resolution over the depth compared to the conventional receive dynamic focusing (CRDF). In addition, it doesn't yield any artifacts associated with the lack of enough transmit acoustic energy shown in the conventional SA imaging technique. The consistent results were obtained with the in vivo breast data. This result indicates that the proposed DSA method could be used for enhancing image quality of medical ultrasound imaging.

Efficient implementation of a real-time dynamic synthetic aperture beamformer

“…However, this simple assumption fails to achieve the optimal lateral resolution since the actual and assumed transmit acoustic field are different [6]. To obtain actual transmit acoustic field, the Field II program is utilized and the parameters used in the simulation is summarized in Table I.…”

Ultrasonic Synthetic Apertures: Review

“…The authors investigated the compound imaging with convex arrays for any number of angles without reducing the frame rate or temporal resolution. The degradation of image quality close to a virtual source was addressed by Kim et al (2012). Authors introduced the dynamic SA where the number of synthetic scan lines for acoustic field superposition is dynamically adjusted based on the transmit acoustic field analysis.…”