Sparse Rectangular and Spiral Array Designs for 3D Medical Ultrasound Imaging.

Area of Science:

• Medical Imaging
• Ultrasound Technology
• Array Signal Processing

Background:

• Three-dimensional (3D) medical ultrasound imaging utilizes two-dimensional (2D) arrays.
• Sparse 2D arrays are investigated to decrease the number of active channels.
• Uniformly arranged sparse 2D arrays offer benefits like reduced side lobe energy and consistent field responses.

Purpose of the Study:

• To introduce two novel uniform sparse array models: sparse rectangular arrays (SRAs) and sparse spiral arrays (SSAs).
• To propose theoretical design rules for transmit (Tx) and receive (Rx) array pairs to suppress grating lobe levels.
• To evaluate the performance of these sparse array models in 3D medical ultrasound applications.

Main Methods:

• Development of two uniform sparse array models: SRAs on a rectangular grid and SSAs on a sunflower grid.
• Design of Tx/Rx array pairs to avoid co-located grating lobes in beam patterns.
• Utilizing computer simulations to analyze array performance, including grating lobe levels and beam widths.

Main Results:

• Both SRA and SSA models were shown to be easily implementable on existing or custom arrays.
• The proposed Tx/Rx array pairs for SRAs and SSAs successfully suppressed peak grating lobe levels below -40 dB.
• These sparse array configurations achieved the desired low grating lobes using approximately 25% of the elements found in dense rectangular arrays.

Conclusions:

• The proposed uniform sparse array models (SRAs and SSAs) offer a significant reduction in active channels for 3D medical ultrasound.
• The designed Tx/Rx array pairs effectively minimize grating lobe interference, enhancing image quality.
• These findings suggest a practical approach to developing more efficient and effective 3D ultrasound systems.