Ahadi Golnaz, Welch Christian S, Grimm Michele J, Fisher David J, Zadicario Eyal, Ernström Karin, Voie Arne H, Hölscher Thilo
Brain Ultrasound Research Laboratory (BURL), University of California, San Diego, 200 West Arbor Drive, San Diego, CA 92103-8756, USA ; Department of Biomedical Engineering, Wayne State University, Detroit, MI 48202, USA.
Department of Radiology, University of California, San Diego, 200 West Arbor Drive, San Diego, CA 92103-8756, USA.
J Ther Ultrasound. 2013 Nov 1;1:22. doi: 10.1186/2050-5736-1-22. eCollection 2013.
The primary goal of this study was to investigate the relationship between increasing output power levels and clot fragmentation during high-intensity focused ultrasound (HIFU)-induced thrombolysis.
A HIFU headsystem, designed for brain applications in humans, was used for this project. A human calvarium was mounted inside the water-filled hemispheric transducer. Artificial thrombi were placed inside the skull and located at the natural focus point of the transducer. Clots were exposed to a range of acoustic output power levels from 0 to 400 W. The other HIFU operating parameters remained constant. To assess clot fragmentation, three filters of different mesh pore sizes were used. To assess sonothrombolysis efficacy, the clot weight loss was measured.
No evidence of increasing clot fragmentation was found with increasing acoustic intensities in the majority of the study groups of less than 400 W. Increasing clot lysis could be observed with increasing acoustic output powers.
Transcranial sonothrombolysis could be achieved in vitro within seconds in the absence of tPA and without producing relevant clot fragmentation, using acoustic output powers of <400 W.
本研究的主要目的是调查在高强度聚焦超声（HIFU）诱导溶栓过程中，输出功率水平增加与血栓破碎之间的关系。
本项目使用了一种专为人类脑部应用设计的HIFU头部系统。将人类颅骨安装在充满水的半球形换能器内部。将人工血栓放置在颅骨内并位于换能器的自然焦点处。使血栓暴露于0至400W的一系列声学输出功率水平下。其他HIFU操作参数保持不变。为了评估血栓破碎情况，使用了三种不同网孔尺寸的过滤器。为了评估超声溶栓效果，测量了血栓重量减轻情况。
在大多数低于400W的研究组中，未发现随着声强增加血栓破碎增加的证据。随着声学输出功率增加，可以观察到血栓溶解增加。
在不使用组织型纤溶酶原激活剂（tPA）且不产生相关血栓破碎的情况下，使用<400W的声学输出功率可在体外数秒内实现经颅超声溶栓。
