外渗
医学
活体显微镜检查
体内
超声波
绒毛尿囊膜
生物医学工程
基底膜
血管通透性
力学指标
病理
内皮
微气泡
微循环
放射科
血管生成
内科学
生物技术
生物
作者
Susanne M. Stieger‐Vanegas,Charles F. Caskey,R. H. Adamson,Katherine W. Ferrara,Fitz-Roy E. Curry,Erik R. Wisner,Katherine W. Ferrara
出处
期刊:Radiology
[Radiological Society of North America]
日期:2007-04-01
卷期号:243 (1): 112-121
被引量:151
标识
DOI:10.1148/radiol.2431060167
摘要
Purpose: To characterize the effect of low-frequency contrast material–enhanced ultrasound on the vascular endothelium and to determine the parameters and techniques required to deliver a therapeutic agent by using the chorioallantoic membrane (CAM) model. Materials and Methods: All in vivo animal procedures were conducted with institutional Animal Care and Use Committee approval. Extravasation of 8.5-nm-diameter fluorescein isothiocyanate–labeled dextran was evaluated in the vasculature of a chick CAM model. Intravital microscopy was performed during contrast-enhanced ultrasound exposure (1.00 or 2.25 MHz); results were compared with results of electron microscopy of the insonated regions. Data acquired after insonation with greater mechanical stress (n = 30 animals) (mechanical index [MI] > 1.3) and with lower mechanical stress (n = 86 animals) (MI < 1.13) were compared with measurements in control conditions (n = 46 animals). The diameter of affected vessels; number of extravasation sites; extravasation rate, area, and location; and changes in endothelial cells and basement membrane were evaluated. Differences were tested with analysis of variance or the Student t test. Results: After ultrasound application, convective transport of the model drug was observed through micron-sized openings with a mean fluid velocity of 188.6 μm/sec in the low-stress class and 362.5 μm/sec in the high-stress class. Electron microscopy revealed micron-sized focal endothelial gaps and disseminated blebs, vacuoles, and filopodia extending across tens of microns. The threshold pressure for extravasation was 0.5 MPa for a transmitted center frequency of 1.00 MHz (MI = 0.5) and 1.6 MPa for a frequency of 2.25 MHz (MI = 1.06); thus, the frequency dependence of the threshold was not predicted simply by the MI. Conclusion: Low-frequency contrast-enhanced ultrasound can increase vascular permeability and result in convective extravasation of an 8.5-nm-diameter model drug. Supplemental material: http://radiology.rsnajnls.org/cgi/content/full/243/1/112/DC1 © RSNA, 2007
科研通智能强力驱动
Strongly Powered by AbleSci AI