心腔内造影剂微气泡后散射与压力的关系及影响因素

我们将应用声学密度法观察与分析声振白蛋白微气泡后散射强度在心动周期中的变化规律，探讨与微气泡大小和压力的关系，阐明后散射随心腔内压力变化的机理，确定各种影响因素对后散射强度与压力间关系的作用。这将为应用声学密度后散射分析法无创性估计心腔内压力提供理论和实验依据，具有潜在的临床应用前景。

The backscatter from the sonicated albumin microbubbles was analyzed using acoustic densitometry in an in vitro heart model and in animal to evaluate the effects of the pressure on the backscatter from sonicated albumin microbubbles. The cyclic change of intensity of the backscatter from the sonicated albumin microbubbles in cardiac cycle was observed with highest intensity in end-diastole and lowest intensity in end-systole. Although the intensity of backscatter in diastole and systole were related to the concentration of microbubbles, the concentration of microbubbles had no effect on the difference of the end-diastolic and end-systolic backscatter. The difference of the end-diastolic and end-systolic backscatter was highly correlated with end-systolic pressure. Our study indicates that it is possible to evaluate the intracardiac pressure non-invasively by analyzing the intracardiac backscatter from the microbubbles with acoustic densitometry.