FoCUS: Fourier-based Coded Ultrasound

TL;DR

This paper introduces a Fourier-based method for implementing coded ultrasound excitation that significantly reduces computational complexity while maintaining image quality, enabling more efficient and deeper ultrasound imaging.

Contribution

The paper presents a novel frequency domain beamforming approach that efficiently integrates pulse compression, reducing computational load without degrading axial resolution.

Findings

Achieves up to 77-fold reduction in computational complexity.

Maintains axial resolution while improving efficiency.

Enhances imaging depth and frame-rate in ultrasound systems.

Abstract

Modern imaging systems typically use single-carrier short pulses for transducer excitation. Coded signals together with pulse compression are successfully used in radar and communication to increase the amount of transmitted energy. Previous research verified significant improvement in SNR and imaging depth for ultrasound imaging with coded signals. Since pulse compression needs to be applied at each transducer element, the implementation of coded excitation (CE) in array imaging is computationally complex. Applying pulse compression on the beamformer output reduces the computational load but also degrades both the axial and lateral point spread function (PSF) compromising image quality. In this work we present an approach for efficient implementation of pulse compression by integrating it into frequency domain beamforming. This method leads to significant reduction in the amount of computations without affecting axial resolution. The lateral resolution is dictated by the factor of savings in computational load. We verify the performance of our method on a Verasonics imaging system and compare the resulting images to time-domain processing. We show that up to 77 fold reduction in computational complexity can be achieved in a typical imaging setups. The efficient implementation makes CE a feasible approach in array imaging paving the way to enhanced SNR as well as improved imaging depth and frame-rate.