Assessing Blood-Brain Barrier Opening and Safety in Rats during Focused Ultrasound Procedure with MRI and Acoustic Cavitation Monitoring

Motivation: There is a lack of comprehensive MRI-based evaluation of low-intensity focused ultrasound (LIFU)-induced blood-brain barrier (BBB) opening in rat models. Goal(s): We aim to develop a safe BBB opening protocol in rat models with jugular vein catheter, using cavitation monitoring and MRI assessment. Approach: We investigated the effects of sonication parameters on BBB opening and tissue damage and the relationship between ultrasound cavitation measures and contrast changes on post-treatment MRI (T1W, T2W, SWI, T2*) Results: Optimal BBB opening was achieved at 0.45 MPa with 10 ms burst length and continuous microbubble injection, confirmed by T1-weighted MRI showing hyperintensity and no brain damage. Impact: The optimized BBB opening and monitoring protocol developed in this study will enable preclinical studies of delivery of the therapeutic compounds across the BBB.