Coded excitation ultrasound: Efficient implementation via frequency domain processing

Modern imaging systems use single-carrier short pulses for transducer excitation. The usage of coded signals allowing for pulse compression is known to improve signal-to-noise ratio (SNR), for example in radar and communication. One of the main challenges in applying coded excitation (CE) to medical imaging is frequency dependent attenuation in biological tissues. Previous work overcame this challenge and verified significant improvement in SNR and imaging depth by using an array of transducer elements and applying pulse compression at each element. However, this approach results in a large computational load. A common way of reducing the cost is to apply pulse compression after beamforming, which reduces image quality. In this work we propose a high-quality low cost method for CE imaging by integrating pulse compression into the recently developed frequency domain beamforming framework. This approach yields a 26-fold reduction in computational complexity without compromising image quality. This reduction enables efficient implementation of CE in array imaging paving the way to enhanced SNR, improved imaging depth and higher frame-rate.