Efficient array beam forming by spatial filtering for ultrasound B-mode imaging.

Area of Science:

• Medical Imaging
• Acoustics
• Signal Processing

Background:

• Conventional array imaging in ultrasonography relies on dynamic receive focusing (DRF).
• DRF methods can be limited in improving image resolution and contrast-to-noise ratio.

Purpose of the Study:

• To propose and evaluate an efficient array beam-forming method using spatial matched filtering (SMF) for ultrasonic imaging.
• To compare the performance of SMF with conventional DRF methods in terms of lateral resolution and contrast-to-noise ratio.

Main Methods:

• Ultrasonic waves are transmitted with a fixed focus.
• Receive echo signals undergo spatial matched filtering based on the system's transmit-receive spatial impulse response.
• Filtered signals are summed without time delays for focused output with low side lobes.

Main Results:

• Analytical beam pattern analysis and simulations demonstrate improved lateral resolution and contrast-to-noise ratio with SMF compared to DRF.
• Experimental results with a linear array confirm findings but highlight practical implementation challenges.
• SMF performance degrades comparably to DRF in the presence of phase aberrations.

Conclusions:

• Spatial matched filtering offers an efficient beam-forming approach for ultrasonic imaging.
• SMF can enhance image quality metrics like lateral resolution and contrast-to-noise ratio.
• Further research is needed to address practical limitations and robustness against aberrations for widespread clinical adoption.