コントラストエコー (超音波造影)

抄録

We have developed a prototype second harmonic/flash echo imaging system for visualizing tissue perfusion. Second harmonic imaging is a new method that exploits the nonlinear properties of microbubble-containing ultrasound contrast agent. In phantom experiments, we obtained excellent harmonic images by eliminating the echoes from tissue-mimicking materials. The hepatic parenchyma was clearly enhanced in animal studies, and myocardial perfusion was visualized in studies using dogs.
Flash echo imaging (FEI) is a new contrast echo imaging technique. In FEI, the strong echoes that are momentarily induced by intermittent ultrasound transmission are detected. The results of our studies indicate that the harmonic mode of FEI is able to visualize microvessels which perfuse organ parenchyma.
The target blood flow can be changed by varying the suspension time for ultrasound transmission. FEI will be expected to visualize the flow rate of perfusion.
Second harmonic imaging and flash echo imaging are expected to expand the capabilities of diagnostic ultrasound systems for visualizing tissue perfusion.