体外模拟实验研究心腔内压力对微气泡后散射强度的影响  

Effects of Pressure on Echocardiographic Backscatter Intensity from Sonicated Albumin:An in vitro Model

作　　者：潘敏[1] 邓又斌[1] 黎春雷[1] 任宏义[2] 刘娅妮[1] 覃勇[1] 白姣[1] 杨好意[1] 毕小军[1] 常青[1] 向慧娟[1] 

机构地区：[1]华中科技大学同济医学院附属同济医院超声影像科,湖北武汉430030 [2]中国三江航天集团湖北航天医院功能检查科

出　　处：《中国医学影像技术》2003年第7期836-839,共4页Chinese Journal of Medical Imaging Technology

基　　金：国家自然科学基金 (39970 30 8)

摘　　要：目的　通过体外模拟实验 ,研究不同压力对声振白蛋白后散射强度的影响 ,并观察显微镜下其直径的变化 ,以进一步证实微气泡散射强度与其直径变化之间的关系 ,并评价运用这一方法无创性估测心腔内压力的可行性。方法　设计一体外模拟心脏模型 ,注入 5 %声振白蛋白后 ,密封容器 ,使微气泡处于悬浮状态并模拟心脏收缩和舒张时的压力变化 ,观察升压和解压后微气泡的后散射强度 ,显微镜同步观察单个微气泡的外形。结果　微气泡后散射时间强度曲线随压力的升高和降低出现周期性的变化 ,压力升高后散射强度达到最低 ,压力解除后散射强度恢复。显微镜下观察到压力升高微气泡体积变小 ,压力解除微气泡体积回复。结论　压力增加显微镜下观察到微气泡直径变小 ,声学密度分析软件则显示后散射强度减弱 ,从而推导后散射强度的减弱主要与微气泡的暂时被压缩有关。然而该方法在检测压力变化的敏感性和准确性上有待进一步提高 ,此外用于检测压力变化的绝对值时还需建立一个准确的校正公式。Objective To investigate the effects of different pressure on sonicated albumin microbubbles by their backscatter time-intensity curves and microscopic views in an in vitro model,and try to confirm the relationship between scattering intensity and bubble size,and consequently evaluate the feasibility of the noninvasive monitoring of intracardiac pressure.Methods An in vitro model for sonographic imaging was built.The system was then closed after 5% sonicated albumin was injected.The water tank was positioned over a stirring device and consequently the bubbles were made suspended.The system was pressurized and depressurized in a random order by a syringe.The backscatter image on ultrasonic equipment and microscopic view for a single bubble were recorded simultaneously.Results The backscatter time-intensity curve of microbubbles changed reversibly with pressurization and depressurization.There was the lowest backscatter intensity during the pressurization,which was recovered during the depressurization.Meanwhile,microscopic view displayed that the bubble's diameter reduced at pressurization and recovered at depressurization.Conclusion An increase of the local pressure leads to a decrease of the bubble's diameter and scattering intensity.It can be concluded that the decrease of the backscatter intensity of microbubbles is attributed to the compressibility of them.However,further improvement of the detection sensitivity and accuracy is required for the cardiac application.And to measure the absolute values of the local pressure,a calibration theory needs to be developed.

关 键 词：微气泡 后散射强度 压力 显微观察 

分 类 号：R445.1[医药卫生—影像医学与核医学]