Visualization of coronary arteriole plexus image by contrast echocardiography

心肌声学造影（MCE）提供了有用的信息，如在毛细血管水平的心肌灌注，血流速度非常低。低机械指数（MI）模式可实现实时灌注成像，而高MI模式则需要间歇成像。本研究的目的是观察心脏小动脉水平的血流灌注。采用Sequoia 512（SIEMENS）在0.075mg/min的YM 454输注过程中使用具有各种机械指数（0.1-0.6）的相干对比成像在短轴视图中进行实时MCE。结果：低MI（0.1-0.2）时，显示均匀的乳浊，随着MI的增加，乳浊逐渐变粗，最后消失。在MI 0.3-0.4处观察到小点和亮线。结论：相对较高的MI（0.3-0.4）可提供血流速度较高的小动脉水平的灌注图像，而MI 0.3-0.4可提供血流速度较高的小动脉水平的灌注图像。这些图像有可能为微循环成像提供新的信息。

Myocardial contrast echocardiography (MCE) provided useful information, such as myocardial perfusion at capillary level in which blood flow speed was extremely low. Low mechanical index (MI) realized real-time perfusion imaging, On the other hand, intermittent imaging was necessary at high MI mode. The aim of this study was to visualize the perfusion at arteriole level of heart.Methods : Open chest dogs were examined. The real-time MCE in the short axis view was performed using coherent contrast imaging with various mechanical index (0.1-0.6) by Sequoia 512 (SIEMENS) during 0.075mg/min. of YM454 infusion. 3D reconstruction was performed by Free-scan (3D-Tec) with the magnetic sensor.Result : Homogeneous opacification was obtained at low MI (0.1-0.2) and according to increase of MI, opacification became coarse and finally faded away. Small dots and bright lines was observed at MI 0.3-0.4. 3-D reconstruction of MCE at MI 0.3 was obtained by free-hand scanning as shown in a figure which shown the fine coronary arteriole complex.Conclusion : Relative high MI (0.3-0.4) provides the perfusion images at arteriole level in which blood flow speed might be high. And those images might provide a new information about microcirculation using MCE.