Arterial Labeling Ultrasound Subtraction Angiography

As a convenient and non-radiation technology, contrast-enhanced ultrasound (CEUS) has been widely used to measure blood flow and perfusion. However, when the contrast agents are flowing into the region of interest (ROI), the ultrasound can enhance all the blood vessels, so it is not nearly possible to observe a specific blood vessel and its downstream perfusion areas like digital subtraction angiography (DSA) or Arterial spin labeling (ASL). This study proposed an arterial labeling ultrasound subtraction angiography (ALUSA) based on phase-change nanodroplets (PCNDs), attempting to achieve noninvasive labeling of a specific blood vessel and ultrasound imaging of downstream blood supply and perfusion in real-time.