Fig. 1.

Analysis of the dynamic changes in power Doppler signal and mean Doppler frequency shift, which supposedly yield volume and velocity, respectively. (a) and (b): power Doppler image M₀(x, y) and mean frequency shift f_mean(x, y) temporally averaged; the red, blue, and green ROIs mark a retinal artery (RA), a retinal vein (RV), and the background (B), respectively. (c) and (d) temporal traces of M₀ and f_mean in the depicted ROIs. (e) and (f): temporal traces in the same ROIs when subtracting the spatially averaged signal over the entire image, i.e. M₀ − 〈M₀〉_x,y, and f_mean − 〈f_mean〉_x,y. See Visualization 1 ^{(23.8MB, avi)} and Visualization 2 ^{(41.4MB, avi)} for the juxtaposed movies of M₀ and f_mean corrected and not-corrected from the spatial average. Removing the spatial average allows to reveal the retinal flow waveforms.