Novel POES Method for Raw RF Signal Recovery in Sparse Synthetic Aperture Ultrasound Acquisition: Preliminary Performance Analysis

Reduction in number of active receive channels, or using sparse arrays, in synthetic aperture-based schemes is one of the attractive approaches for reducing the ultrasound system cost and complexity. However, reconstructed images obtained from such schemes suffer from poorer image quality compared to that obtained using data from full-aperture. Several methods of recovering the missing data from sparse data acquisition have been demonstrated to contribute towards improved image quality. However, most of the reported random sparse recovery strategies such as compressed sensing (CS) involve optimization, and thus have increased computational complexity. Recently, a novel time delay difference-based approach called Projection Onto Elliptical Sets (POES) was developed to recover missing frame data in sparse transmit and limited receive aperture acquisition. In this study, the recovery performance of the novel POES method is evaluated on data acquired using typical sparse receive array configuration in diverging beam synthetic aperture transmit (DBSAT) scheme. Two random sparse distribution based on uniform and Gaussian were evaluated for 50%, 75% and 87.5% undersampling. The results suggested that POES method resulted in better CNR and lower NRMSE values in comparison to CS. The recovery time taken by POES method was 0.0723 ± 0.0377 seconds as opposed to 5-6 hours required for CS. Thus, POES method is demonstrated to be a practical, computationally more efficient alternate approach of recovering missing channel information for sparse random receive DBSAT data.