Pulse Stretching Correction for Improving Ultrasound Image Resolution

Area of Science:

• Medical imaging
• Ultrasound technology
• Signal processing

Background:

• Wide band large-aperture transducer arrays enable high-resolution ultrasound imaging with deep penetration using synthetic aperture (SA) techniques.
• Long array signals in SA imaging can cause resolution degradation and aliasing due to pulse stretching, particularly in the near field with large reflection angles.

Purpose of the Study:

• To propose and validate a novel pulse stretching correction (PSC) method for synthetic aperture ultrasound imaging.
• To mitigate resolution degradation and image aliasing caused by pulse stretching in near-field ultrasound data.

Main Methods:

• Developed a mathematical model for pulse stretching.
• Reformulated the delay-and-sum SA equation into a common-angle form.
• Applied frequency-domain correction to eliminate pulse stretching in the reflection angle domain.

Main Results:

• Simulations and experimental results demonstrated the effectiveness of the PSC method.
• The technique successfully suppressed shallow noise.
• Significant improvement in image resolution was observed.

Conclusions:

• Pulse stretching correction is an effective method for enhancing synthetic aperture ultrasound imaging.
• PSC addresses key limitations of current SA techniques, improving image fidelity.
• This approach holds promise for clearer and more accurate ultrasound diagnostics.