Padial L R, Chen M H, Vuille C, Guerrero J L, Weyman A E, Picard M H
Cardiac Unit, Massachusetts General Hospital, Boston 02114, USA.
J Am Soc Echocardiogr. 1995 May-Jun;8(3):285-92. doi: 10.1016/s0894-7317(05)80039-2.
The purpose of this study was to determine in an in vitro model the effect of pulsatile pressure on the decay of echocardiographic contrast agents. Use of contrast agents for quantitative assessment of perfusion requires understanding of the factors controlling their rates of disappearance. Prior studies have shown that constant pressure affects the rate of disappearance of these agents. It is not known whether pulsatile pressure influences the rate of decay of contrast agents. In an in vitro chamber, three contrast agents (Albunex, hand-agitated saline solution, and hand-agitated Angiovist) were exposed to pulses of pressure at three rates (30, 60, and 120 pulsations/min), keeping pressure characteristics (peak, nadir, and mean) within a narrow range. Five injections were performed for each agent at each rate. Two-dimensional echocardiographic images of the effects of contrast material were recorded from injection until total disappearance. Videointensity was measured and time-intensity curves were generated. These curves of intensity decay were fitted to an exponential decay function (I = Ae-lambda t) and the velocity of decay (lambda) was used for comparisons. For all agents, intensity of contrast decreased over time. Saline solution and Angiovist, but not Albunex, showed pulsatile decreases in intensity of contrast with each peak pressure and partial recovery of contrast intensity with each nadir pressure. (ABSTRACT TRUNCATED AT 250 WORDS)
本研究的目的是在体外模型中确定脉动压力对超声心动图造影剂衰减的影响。使用造影剂进行灌注的定量评估需要了解控制其消失速率的因素。先前的研究表明，恒定压力会影响这些造影剂的消失速率。目前尚不清楚脉动压力是否会影响造影剂的衰减速率。在一个体外腔室中，三种造影剂（白蛋白微球、手动搅拌的盐水溶液和手动搅拌的安吉奥维斯特）以三种速率（30、60和120次搏动/分钟）接受压力脉冲，同时将压力特征（峰值、谷值和平均值）保持在狭窄范围内。每种造影剂在每个速率下进行五次注射。从注射直至完全消失，记录造影剂效果的二维超声心动图图像。测量视频强度并生成时间-强度曲线。将这些强度衰减曲线拟合为指数衰减函数（I = Ae-lambda t），并使用衰减速度（lambda）进行比较。对于所有造影剂，造影剂强度随时间降低。盐水溶液和安吉奥维斯特，但白蛋白微球未出现这种情况，在每个峰值压力下造影剂强度呈脉动性降低，且在每个谷值压力下造影剂强度部分恢复。（摘要截断于250字）
