Ultrafast compound doppler imaging: A new approach of doppler flow analysis

This work applies the concept of compounded plane wave transmissions at very high frames rates of some KHz for ultrafast Doppler analysis over a large region of interest. As this compound imaging method has a similar quality to the standard focusing method but is 10 times faster, it is possible to generate fast Doppler images at frame rates of 300Hz. This frame rate is able to visualize transient phenomena and to display duplex modes with simultaneous color and spectrum analysis for each pixel of the image. The interest of the method is not restricted to high velocity flows; by optimizing the quality of the ultrasonic compounded image, it is possible to image very small velocity flows. This method is applied to a functional imaging of the rat brain by detecting changes in the flow after a drug injection.