Real-Time System for High Frame Rate Vector Flow Imaging

In a recently proposed high frame rate (HFR) Vector Flow Imaging (VFI) method, the displacements between consecutive beamformed radiofrequency (RF) frames are estimated from the corresponding phase shifts recorded in the frequency domain. Although such method is highly efficient, dedicated hardware would still be needed for a real-time implementation. In this work, we further reduce the computational load by processing demodulated and downsampled baseband (BB) data. Possible undesired effects on the accuracy of the proposed method were assessed. With respect to the RF processed data, simulations and experimental tests showed an average bias lower than 0.6%. A real-time version of the algorithm was implemented on the ULA-OP 256 system, including a high-speed clutter filter and the BB-VFI processing module. Preliminary tests showed that the real-time implementation can sustain up to 100k vector velocity estimates per second.