Synthetic Aperture Ultrasound Imaging through Adaptive Integrated Transmitting-Receiving Beamformer

Area of Science:

• Ultrasound Imaging
• Medical Imaging
• Signal Processing

Background:

• Synthetic aperture (SA) imaging offers advantages for ultrafast ultrasound, enabling full medium insonification and dynamic focusing.
• SA techniques allow for adaptive beamforming in transmission and reception, improving image quality.

Purpose of the Study:

• To reformulate SA beamformer design as a one-way beamformer problem on a virtual array.
• To enhance resolution and contrast in ultrafast ultrasound imaging using adaptive minimum variance (MV) beamforming.

Main Methods:

• Formulation of SA transmit and receive beamformer design as a one-way beamformer on a virtual array.
• Utilizing an enlarged virtual aperture for improved resolution.
• Applying adaptive minimum variance (MV) beamforming with enhanced covariance matrix estimation.

Main Results:

• The new method achieves a virtual aperture length equal to the sum of transmit and receive apertures, enhancing resolution.
• Improved covariance matrix estimation enables superior adaptive MV beamforming.
• Validation through simulations and experimental data shows higher generalized contrast to noise ratio (GCNR) and maintained or decreased full width at half maximum (FWHM).

Conclusions:

• The proposed virtual array method significantly enhances image resolution and contrast in ultrafast SA ultrasound imaging.
• This approach offers a reduced computational burden compared to existing MV-based methods.
• The findings demonstrate a practical advancement for high-performance ultrasound imaging systems.