Lankford Miles, Behm Carolyn Z, Yeh James, Klibanov Alexander L, Robinson Peter, Lindner Jonathan R
Cardiovascular Division, University of Virginia, Charlottesville, Virginia, USA.
Invest Radiol. 2006 Oct;41(10):721-8. doi: 10.1097/01.rli.0000236825.72344.a9.
Molecular imaging with contrast-enhanced ultrasound (CEU) relies on the detection of microbubbles retained in regions of disease. The aim of this study was to determine whether microbubble attachment to cells influences their acoustic signal generation and stability.
Biotinylated microbubbles were attached to streptavidin-coated plates to derive density versus intensity relations during low- and high-power imaging. To assess damping from microbubble attachment to solid or cell surfaces, in vitro imaging was performed for microbubbles charge-coupled to methacrylate spheres and for vascular cell adhesion molecule-1-targeted microbubbles attached to endothelial cells.
Signal enhancement on plates increased according to acoustic power and microbubble site density up to 300 mm. Microbubble signal was reduced by attachment to solid spheres during high- and low-power imaging but was minimally reduced by attachment to endothelial cells and only at low power.
Attachment of targeted microbubbles to rigid surfaces results in damping and a reduction of their acoustic signal, which is not seen when microbubbles are attached to cells. A reliable concentration versus intensity relationship can be expected from microbubble attachment to 2-dimensional surfaces until a very high site density is reached.
超声造影（CEU）分子成像依赖于对疾病区域中留存的微泡进行检测。本研究的目的是确定微泡与细胞的附着是否会影响其声学信号的产生及稳定性。
将生物素化微泡附着于链霉亲和素包被的平板上，以得出低功率和高功率成像期间密度与强度的关系。为评估微泡附着于固体或细胞表面时的衰减情况，对与甲基丙烯酸酯球体电荷耦合的微泡以及附着于内皮细胞的靶向血管细胞黏附分子-1的微泡进行体外成像。
平板上的信号增强随声功率和微泡位点密度增加，直至300毫米。在高功率和低功率成像期间，微泡附着于固体球体时信号减弱，但附着于内皮细胞时仅在低功率下信号有轻微减弱。
靶向微泡附着于刚性表面会导致衰减并使其声学信号减弱，而微泡附着于细胞时则不会出现这种情况。在达到非常高的位点密度之前，微泡附着于二维表面时可预期有可靠的浓度与强度关系。
