Figure 4.

Multi scale flow velocity quantification: a. Velocity map. In (i) velocity is signed along depth direction revealing upward (blue) and downward (red) flow. In (ii) the amplitude of the velocity field is depicted. b. Flow rate quantification illustrated in a small region (white-dashed box in A.ii): after skeletonization, the radius is automatically estimated in all vessels (i). Flow velocity is then computed along the centreline points (ii) and flow rate is then measured for each segment assuming a Poiseuille flow (iii). c. Analysis of flow rate as a function of radius in a large range of vessels reveals a power law with an exponent of 2.62. X and Y axis are in log scale. d. Flow velocity distribution of MB.