Ultrasound-guided microbubble-mediated brain therapy with a modular transmit/receive phased array

Abstract

The development of low-cost, ultrasound-guided focused ultrasound (USgFUS) treatment platforms is expected to advance the adoption of microbubble (MB)-mediated brain therapy by improving access to the technology. Our group has designed and fabricated clinical-scale transmit/receive phased array systems for MB-mediated USgFUS brain therapy. Acoustic field simulations were carried out to optimize array element placement, and transducer scaffolds were constructed using 3D printing techniques. These devices have been employed for skull computed tomography-array registration, 3D spatial mapping of MB activity in vivo through ex-vivo human skullcaps via noninvasive aberration correction methods, and we have harnessed this spatiotemporal cavitation information to calibrate exposure levels for safe volumetric blood-brain barrier opening. At higher exposure levels, we have demonstrated the ability of 3D MB imaging data to predict the tissue damage volume distributions induced during nonthermal brain ablation. Ultrafast processing of acoustic emissions data has been shown to uncover MB dynamics hidden by conventional whole-burst temporal averaging, and can inform temporal undersampling strategies when millisecond-long tone bursts are applied. Machine learning approaches can assist with image-based classification of MB activity, which may result in finer control of the induced bioeffects. This talk will focus on our recent results obtained with a novel modular USgFUS phased array system.