Conventional Ultrasound (US) Doppler methods for blood flow imaging are limited to velocity estimations only in the axial direction, i.e. along the beam direction. Transverse oscillations (TO) methods extend blood investigations towards multidimensional estimates, and detailed descriptions of complex and fast blood flows are achievable by high frame-rate (HFR) imaging methods. In this work, TO are coupled with plane-waves (PWs) to reconstruct radio-frequency (RF) images with bi-directional oscillations in the pulse-echo field. The achieved RF images are exploited by a 2D phase-based displacement estimator to produce 2D-vector flow maps. A preliminary simulation study confirmed the capability of the method to produce the designed oscillations in the RF pulse-echo fields as well as the possibility to obtain 2D-vector maps with errors lower than 10% in many different conditions.
['Matteo Lenge', 'Alessandro Ramalli', 'A. Cellai', 'Piero Tortoli', 'Christian Cachard', 'Hervé Liebgott']
A new method for 2D-vector blood flow imaging based on unconventional beamforming techniques