Super-Resolution Ultrasound: From Data Acquisition and Motion Correction to Localization, Tracking, and Evaluation

Super-resolution ultrasound (SRUS) imaging through localizing and tracking microbubbles (MBs), also known as ultrasound localization microscopy (ULM), has achieved unprecedented resolution in deep tissue in vivo. In this review, we will focus on the key technical steps of ULM, including data acquisition and tissue clutter removal, motion correction, localization, tracking, and final image visualization, as well as offering the authors' perspectives of the techniques. In each of the technical steps, we review what has been done and the state of the art and describe the key factors and parameters that influence each step, existing issues, and considerations when choosing the parameters. Finally, methods for evaluation of ULM image quality with or without ground truth are also reviewed.