A New Motorized MR-Guided Ultrasound System for the Delivery of Large Molecules to the Rodent Brain.

Focused ultrasound combined with microbubbles injection has shown its potential to transiently disrupt the Blood Brain Barrier (BBB), allowing the delivery of large molecules to the Central Nervous System (CNS). However, the phenomenon has still to be investigated as the optimal parameters remain unknown up to date. To do so, we developed a new MR-guided motorized system, allowing the displacement of the transducer within preclinical magnets in order to choose the location of the opening. We demonstrated the capabilities of our system by opening the BBB along arbitrary trajectories. We also show the existence of an acoustic pressure threshold for BBB disruption estimated at about 0.3 MPa at 1.5 MHz by testing different acoustic conditions on the same animal. Finally, we investigated the BBB opening efficiency with the duty cycle. We proved that the disruption was greater with higher duty cycle. [ABSTRACT FROM AUTHOR]