Department of Biomedical Imaging and Radiological Sciences, School of Biomedical Science and Engineering, National Yang-Ming University, 11221 Taipei, Taiwan.
J Acoust Soc Am. 2009 Dec;126(6):3344-9. doi: 10.1121/1.3242376.
It has been shown that focused ultrasound (FUS) is capable of noninvasive and reversible disruption of the blood-brain barrier (BBB) at target regions when applied in the presence of ultrasound contrast agent (UCA). The purpose of this study was to investigate the effects of UCA dose on the reversibility of BBB disruption induced by the same acoustical power of FUS. Sonications were applied at an ultrasound frequency of 1 MHz with a 5% duty cycle and a repetition frequency of 1 Hz. The brains of 66 male Sprague-Dawley rats were subjected to sonications with three doses of UCA. BBB integrity was evaluated via femoral vein injection of Evans Blue (EB) while the rats were anesthetized. The relationship between UCA dose and the region of EB extravasation was evaluated at an acoustic power of 1.43 W. The BBB disruption, as indexed by the amount of EB extravasation, was the largest immediately after the sonications. The quantity of Evans blue extravasation decreased as a function of time at various UCA doses. This study demonstrates that the appropriate dose of UCA not only enhance the BBB opening but also effectively aid in controlling the duration of BBB disruption.
已有研究表明，在超声对比剂（UCA）存在的情况下，聚焦超声（FUS）能够在靶区无创且可逆地破坏血脑屏障（BBB）。本研究旨在探讨不同剂量的 UCA 对 FUS 相同声功率致 BBB 破坏的可逆性的影响。声处理采用 1MHz 超声频率、5%占空比和 1Hz 重复频率。66 只雄性 Sprague-Dawley 大鼠的大脑接受了三种剂量 UCA 的声处理。当大鼠处于麻醉状态时，通过股静脉注射 Evans Blue（EB）来评估 BBB 的完整性。在 1.43W 的声功率下，评估了 UCA 剂量与 EB 外渗区域之间的关系。以 EB 外渗量为指标的 BBB 破坏在声处理后即刻最大。在不同 UCA 剂量下，EB 外渗的量随时间呈下降趋势。本研究表明，适当剂量的 UCA 不仅能增强 BBB 开放，而且能有效控制 BBB 破坏的持续时间。
