Implementation of constrained swept synthetic aperture using a mechanical fixture

Area of Science:

• Medical Imaging
• Ultrasound Technology
• Biomedical Engineering

Background:

• Ultrasound resolution and detectability depend on imaging array size, crucial for deep imaging like liver lesion diagnosis.
• Swept synthetic aperture (SSA) imaging enhances effective aperture size using motion but requires complex external tracking.
• Current SSA methods are limited by bulky fixtures and external motion tracking, hindering clinical accessibility.

Purpose of the Study:

• To develop a simplified SSA imaging approach using a linear sliding fixture.
• To estimate transducer motion directly from ultrasound data, eliminating external tracking needs.
• To improve resolution and target detectability in ultrasound imaging for liver lesion diagnosis.

Main Methods:

• Constraining transducer motion with a simple linear sliding fixture.
• Estimating lateral transducer motion using speckle tracking or channel correlation within ultrasound data.
• Demonstrating the technique's efficacy through simulations and phantom experiments, including ex vivo tissue imaging.

Main Results:

• Accurate estimation of lateral transducer motion with errors under 83 μm across a 50 mm sweep in simulations.
• Experimental improvements of up to 61% in resolution and 33% in lesion detectability.
• Successful SSA image formation with enhanced quality even when imaging through ex vivo tissue layers.

Conclusions:

• The developed approach simplifies SSA imaging by integrating motion estimation directly into the ultrasound data.
• This method significantly improves resolution and lesion detectability, making SSA imaging more accessible.
• The findings pave the way for testing SSA imaging in clinical settings for improved diagnostic capabilities.