Scanning Ultrasonic PW-Flowmeter to Characterize In Vivo Vessel Structures

In medical ultrasound the improvement of blood flow measurement accuracy is still a very demanding goal, because currently used ultrasonic pulsed-wave flowmeters cannot map low flow velocities patterns in the microvasculature. The scanner resolution is limited by the applied acoustic wavelength. Shorter wavelengths result in better scanning resolution and improved scattering characteristics of blood, but suffer an increasing attenuation in tissue, thereby reducing the useful interrogation depth. Such scanners are able to visualize superficial tissue up to a few centimeters deep depending on the particular wavelength and tissue properties. We present results shown as a 3D visualization of the volumetric flow velocity of pervaded tissue cuboid color-coded and we report on an in vivo experiment (human tissue).