2D Tracking Doppler: A new method to limit spectral broadening in pulsed wave doppler

Transit time broadening is a major limitation in Pulsed Wave (PW) Doppler, especially when the angle between the flow direction and the ultrasound beam is large. The limited frequency resolution may give severe overestimation of blood velocities, and finer details in the spectral display are lost. By using plane wave transmissions and parallel receive beamforming PW-Doppler signals can be acquired simultaneously in a larger region. This enables tracking of the moving blood scatterers over a longer spatial distance to avoid transit time broadening. In this work, the new method was tested using in vitro and in vivo ultrasound recordings of the carotid artery. The resulting Doppler spectra showed reduced spectral broadening compared to Doppler spectra generated by the Welch´s method.