Non-Localization Super-Resolution Velocity Evaluation Based on the Trail of Point Spread Functions (TPSF)

Ultrasound localization microscopy (ULM) can obtain super-resolved flow velocity maps by localizing and tracking microbubbles. Recently, some non-localization based super-resolution ultrasound (SRUS) methods were proposed, such as ultrasound diffraction attenuation microscopy (UDAM). Flow velocity estimation without tracking is still a limitation in these methods. Here, we propose a novel flow velocity estimating method based on the trail of the point spread function (TPSF). Briefly, the flow velocity and direction are estimated by the instantaneous slope of the microbubbles moving trail curves, and the commonly used tracking procedure can be therefore replaced. The TPSF method converts the point detection task in ULM into a line detection problem and realizes dimension raising.