Super Resolution Ultrasound Imaging: investigating the effect of processing parameters and flow orientation on image quality

Abstract

Super Resolution (SR) Ultrasound (US) imaging combines high spatial resolution with high penetration depth imaging to an extent that is currently not available by other in vivo imaging modalities. SRUS relies on detection, localization and tracking of single microbubbles (MBs) in blood vasculatrue. This study focuses on how to set SRUS processing parameters to obtain a SR image and on the effect of flow direction on the resolution. To analyze the effect of processing parameters, acquisitions of chicken embryos and of ex vivo rabbit kidneys were performed and SRUS processing was done with different parameter settings. The effect of flow direction was measured using a custom-made phantom with two crossing tubes and using flow simulations of that phantom. Image filtering and the choice of sufficiently small pixels in the B-Mode image reconstruction showed to have the most effect on SRUS images. SRUS images were shown to be independent of flow direction whereas the flow direction affected the resolution of power Doppler images. This study provides a guideline for setting SRUS processing parameters.