摘要
目的 探讨声学密度法在犬心腔内声振白蛋白造影剂后散射时间 强度曲线随心动周期的变化规律 ,分析收缩期压力和造影剂剂量的改变对其后散射强度的影响。方法 取主动脉根部短轴切面 ,经多巴酚丁胺逐步升压后 ,周围静脉注射不同剂量声振白蛋白造影剂 ,记录不同收缩期压力和不同造影剂剂量时的后散射二维图像 ,并与右室压力曲线同步。结果 心腔内微气泡后散射时间 强度曲线随心动周期发生可逆性的周期性变化 ,收缩末期后散射强度达到最低 ,舒张末期恢复原强度 ;舒张末期和收缩末期后散射强度之差随收缩期压力的升高逐渐加大 ,与收缩期压力高低相关 (r=0 .64 ,P <0 .0 0 0 1 ) ,与造影剂剂量无关 (P=0 .57)。结论 压力作用致微气泡后散射强度的减弱主要与微气泡的暂时被压缩有关 ,利用声学密度法 ,通过观察心腔内微气泡后散射时间 强度曲线的变化 。
Objective To observe the cardiac cyclic changes of backscatter time-intensity curve from intracardiac sonicated albumin microbubbles in dogs,and analyze the effects of systolic pressure and different contrast doses on the backscatter intensity using acoustic densitometry.Methods A 7-F catheter was placed within right ventricle through a femoral vein in nine anesthetized dogs.The echocardiographic examination showed the short-axis images of the aortic root.Ventricular pressure was increased by administration of dobutamine(β 1-adrenoceptor agonist).And different doses of sonicated albumin microbubbles were injected intravenously.The next step was to record the two-dimensional images from intracardiac backscatter at different systolic pressure and different contrast doses,which synchronized with right ventricular pressure curve.Results The intracardiac backscatter time-intensity curve changed reversibly with intracardiac pressure in cardiac cycle.There was the lowest backscatter intensity in end-systole,which was recovered in end-diastole.There was a negative correlation between systolic pressure and ESIB(r= -0.29 ,P= 0.05 ),but not between systolic pressure and EDIB(r= -0.068 ,P= 0.66 ).The ED-ES increased with the elevation of systolic pressure and highly correlation could be found (r= 0.64 ,P< 0.000 1 ).The EDIB and ESIB of sonicated albumin microbubbles decreased in response to the enhancement of contrast doses(P< 0.000 1 ,P< 0.000 1 ),but the ED-ES kept stable( P= 0.57 ).Conclusions The decrease of backscatter intensity induced by an increase in the systolic pressure was attributed to the compression of microbubbles.It is possible to evaluate the intracardiac pressure by observing the backscatter time-intensity curve of microbubbles,and quantitating ED-ES using acoustic densitometry.
出处
《中华超声影像学杂志》
CSCD
2003年第2期105-108,共4页
Chinese Journal of Ultrasonography
基金
国家自然科学基资助项目 ( 39970 30 8)
关键词
声学密度法
压力
微气泡
散射强度
心腔
Ultrasonography
Contrast media
Acoustic densitometry
Pressure
