Staff Detail: Kenji Yoshida


Kenji Yoshida
Associate Professor 
Contrast enhanced ultrasound, ultrasound and near infrared fl uorescence dual imaging, Measurement of acoustic property of tissue, Biological eff ect of ultrasound, nano- and microbubble 

Research Subject

Ultrasound and near infrared fluorescence dual imaging using nano- and micrbubbles

Ultrasound and near infrared fluorescent dual imaging have been developed. By a combination of near infrared fluorescent with higher resolution and ultrasound with better penetration depth, we propose an imaging method for visualizing vessels near surface and in deeper tissue. We have developed the contrast agents which can work in both imaging methods, in particular, fluorescent nanobubbles for imaging of lympha system(lympha vessels and lympha nodes). Nanobubbles based on liposome have internal gas as ultrasound contrast agents and indocyanine green derivatives is supported to the lipid bilayer membrane. The ability of contrast agents could be confirmed by using clinical equipment.

High-sensitive ultrasound imaging of small vessels

Ultrasound imaging for visualizing small vessels with diameter from several ten to several hundred micrometers have been studied. We proposed contrast enhanced active Doppler ultrasound imaging (CEADUS), where the motions of contrast agents caused by acoustic radiation force of incident ultrasound are visualized. In conventional method, the image has only the information on echo intensity. On the other hand, CEADUS utilize the phase of echo signal to improve image quality. Based on phantom experiments, we demonstrated that CEADUS enabled to visualize a simulated channel with high sensitivity. Now we are improving shortcomings of CEADUS such as poor frame rate and motion artifact to develop to effective method.