High frame rate ultrasound displacement vector imaging

The tissue displacement vector obtained with high frame-rate imaging may provide valuable diagnostic information. Measuring 2D displacements caused by rapid dynamic processes, such as arterial pulse waves or shear waves, requires inter-frame displacement precision in the micrometer range. Conventional vector estimation techniques do not satisfy this criterion. In this paper we describe a new robust technique for estimating the 2D displacement vector with the required precision. Echoes reflected from a moving scatterer will cause unique delays along the elements of an array. For each pair of elements the solution for the new scatterer position is exact. By averaging many pair-wise estimates we find a robust estimation of the new scatterer location and thereby the displacement vector. We successfully tested our method on rotating scatterers and on a pulsating carotid artery in transverse view.