Recursive Imaging for Tracking High Density Scatterers in Super-Resolution Imaging

A key component of super-resolution ultrasound imaging (SRI) is the detection and tracking of scatterers. These scatterers can be microbubbles (MBs) in SRI, or erythrocytes in SUper Resolution ultrasound imaging using Erythrocytes (SURE). To ensure the reliability of MBs tracking in SRI, the MBs must be sparse. However, the sparse distribution of the MBs necessitates several minutes of acquisition. In contrast, there are large numbers of erythrocytes in SURE. Increasing the number of scatterers can reduce the acquisition time, however tracking uncorrelated and high-density scatterers is quite challenging. It is hypothesized that recursive Synthetic Aperture (SA) imaging will increase the detecting and tracking abilities of the high-density and non-separable scatterers. The hypothesis was verified using a hydrogel 3D-printed micro-flow phantom and a Sprague-Dawley rat kidney. The results show that using recursive SA imaging provides better detection and tracking of high-density and non-separable targets, as well as a smoother and more parabolic velocity profile than conventional SA imaging.