Coherent Bistatic 3-D Ultrasound Imaging Using Two Sparse Matrix Arrays

Area of Science:

• Medical Imaging
• Ultrasound Technology
• Biomedical Engineering

Background:

• Recent advancements in high frame rate 3-D ultrasound imaging involve flexible acquisition systems, transmit (TX) sequences, and transducer arrays.
• Compounding multiangle transmits of diverging waves with 2-D matrix arrays is effective, but anisotropy in contrast and resolution persists with single transducers.

Purpose of the Study:

• To demonstrate a bistatic imaging aperture using two synchronized 32x32 matrix arrays for fast interleaved transmits and simultaneous receive (RX).
• To evaluate aperture efficiency for high volume rate imaging comparing sparse random and fully multiplexed arrays.
• To analyze the performance of the bistatic acquisition scheme in phantom studies mimicking abdominal and aortic imaging.

Main Methods:

• Evaluated aperture efficiency of sparse random versus fully multiplexed arrays for single-array high volume rate imaging.
• Implemented a bistatic imaging system with two synchronized 32x32 matrix arrays for interleaved transmits and simultaneous RX.
• Tested the dual-array system on a wire phantom and a dynamic setup simulating the human abdomen and aorta.

Main Results:

• Sparse arrays showed comparable resolution but lower contrast than fully multiplexed arrays, yet minimized motion decorrelation.
• The dual-array aperture improved spatial resolution, reduced average volumetric speckle size by 72%, and decreased axial-lateral eccentricity by 8%.
• In the aorta phantom, angular coverage increased threefold, enhancing wall-lumen contrast by 16% compared to single-array imaging.

Conclusions:

• The demonstrated bistatic imaging aperture effectively improves spatial resolution and contrast in high frame rate 3-D ultrasound.
• This dual-array approach overcomes single-transducer limitations, offering significant benefits for dynamic imaging applications like abdominal and vascular ultrasound.