2011/08/19 by Gesthimani Samiotaki, Fotios Vlachos, Yao‐Sheng Tung +1 · 1 citation
Engineering · Materials Science · Medicine · #Advanced MRI Techniques and Applications #Ultrasound and Cavitation Phenomena #Ultrasound and Hyperthermia Applications
paper · doi:10.1002/mrm.23063
openalex publication_date 2011/08/19 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
Focused ultrasound in conjunction with the systemic administration of microbubbles has been shown to open the blood-brain barrier (BBB) selectively, noninvasively and reversibly. In this study, we investigate the dependence of the BBB opening's reversibility on the peak-rarefactional pressure (0.30-0.60 MPa) as well as the microbubble size (diameters of 1-2, 4-5, or 6-8 μm) in mice using contrast-enhanced T(1)-weighted (CE-T(1)) MR images (9.4 T). Volumetric measurements of the diffusion of Gd-DTPA-BMA into the brain parenchyma were used for the quantification of the BBB-opened region on the day of sonication and up to 5 days thereafter. The volume of opening was found to increase with both pressure and microbubble diameter. The duration required for closing was found to be proportional to the volume of opening on the day of opening, and ranged from 24 h, for the smaller microbubbles, to 5 days at high peak-rarefactional pressures. Overall, larger bubbles did not show significant differences. Also, the extent of BBB opening decreased radially towards the focal region until the BBB's integrity was restored. In the cases where histological damage was detected, it was found to be highly correlated with hyperintensity on the precontrast T(1) images.