Ultrafast ultrasound imaging in acoustic microbubble trapping

The lack of actively targeted nanocarriers and a low drug concentration in lesions are two of the main problems in targeted therapy for clinical use. In this paper, an ultrasound-induced trapping and ultrafast imaging system for flowing microbubbles is proposed to increase the effective drug dose and achieve real-time positioning. A finite element method model is established to analyze microbubble tracing in a fluid flow model at 2.5 MHz, which demonstrates how the interaction of acoustic radiation force (ARF) and flowing drag force is able to trap microbubbles and move them to a specific location. This motion can be explicitly imaged and captured by ultrafast plane wave imaging with a 1D array ultrasound probe at 18 MHz. The use of this plane wave and ARF technique can be beneficial for fast localization, monitoring, and manipulation of drug delivery bubbles for targeted release at 10 mm depth in a noninvasive and feasible way. Therefore, this ultrasound technology can be a useful tool to increase the local drug concentration in an accurate location for clinical use.