Ultrasound Doppler vector tomography measurements of directional blood flow

An experimental system has been developed to verify the possibility of detecting flow activity using a technique called ultrasound Doppler vector tomography. A tomography algorithm is used to reconstruct blood flow vector fields using data from computer-controlled ultrasound continuous-wave Doppler scanning equipment. The result is a picture in which the brightness variations represent the reconstructed values of the curl of the velocity field (inverted delta x v). Continuous ultrasound is transmitted into a region with flow activity and the Doppler-shifted signals are received. To obtain measurement data suited for fan beam tomography, the scanning is performed in a plane from points encircling the region. Reconstructions have been achieved using measurement data from two different flow phantoms. A comparison between the experimental results and simulations shows good conformity.