“…The common ultrasound imaging methods in clinics or hospitals include the grayscale ultrasonic (GSUS), Doppler ultrasonic (DUS), and contrast-enhanced ultrasonic (CEUS) imaging. − In particular, the DUS imaging method is used for guiding the navigation of a nanoparticle microswarm in real time, which is beneficial for active endovascular delivery . The CEUS imaging method has achieved various clinical successes, such as in the diagnosis of tumors, lymph node metastasis, diverse inflammation, acute kidney injury, etc. − In comparison to the GSUS and DUS imaging modalities, the CEUS imaging modality exhibits improved imaging resolution and sensitivity of the ultrasonic diagnosis, as it utilizes ultrasonic contrast agents, such as microbubbles (MBs), nanobubbles (NBs), etc., which enhance the echo-backscatter. ,− For instance, the use of submicron sized “NBs” ultrasound contrast agents enable realizing the early diagnosis of Type 1 Diabetes (T1D) through the specific accumulation of NBs within the pancreatic islets . In another study, MBs-based ultrasound contrast agents were injected intravenously to facilitate the transcranial imaging of the cerebrovascular flow at the micrometer scale through ultrasound localization microscopy .…”