Skill of intravenous ultrasonic contrast agent for evaluation of microcirculation of human organs and its assessment for clinical use.

从准确诊断心肌缺血等灌注异常的临床角度出发，需要在相当长的一段时间内显示微循环的精细图像。该方法应该是安全的，对物理或血流动力学条件没有任何副作用。在本研究中，我们利用氟碳气体微泡，结合二次谐波成像和间歇照射的方法，研究了声学造影术。为探讨造影剂超声成像设备的最佳配置，在体外实验中考察了超声频率、声功率、超声间歇照射间隔、病灶位置等因素的影响。因此，在犬实验中观察心肌混浊和血流动力学的影响。最后，圈套造成非血流限制性冠状动脉狭窄。这项研究表明，在给予血管扩张药物后，超声心动图可以检测到危险区域。

It has been needed to visualize the fine image of microcirculation for considerably lasting period from the standing point of accurate clinical diagnosis of perfusion abnormalities, such as myocardial ischemia. The method should be safe without any side-effect to the physical or hemodynamic conditions. In the present research, we studied contrast ultrasound technique using microbubbles with fluorocarbon gas, combined with second harmonic imaging and intermittent irradiation method. To investigate the optimum setup of the ultrasound equipment for imaging the contrast agent, effect of ultrasound frequency, acoustic power, interval of intermittent irradiation of ultrasound, position of focus was examined in vitro study. Consequently, the opacification of the myocardium and hemodynamic influence was examined in canine experiment. Finally, the non flow limiting coronary stenosis was produced by a snare. This study revealed that the the area at risk was detected after administration of vasodilating drugs by using contrast echocardiography.