Mapping the arterial vascular network in an intact human kidney using hierarchical phase-contrast tomography.

The architecture of kidney vasculature is essential the organ's specialised functions, yet is challenging to structurally map in an intact human organ. Here, we combined hierarchical phase-contrast tomography (HiP-CT) with topology network analysis to enable quantitative assessment of the intact human kidney vasculature, from the renal artery to interlobular arteries. Comparison with kidney vascular maps described for rodents revealed similar topologies to human, but human kidney vasculature possessed a significantly sharper decrease in radius from hilum to cortex, deviating from theoretically optimal flow resistance for smaller vessels. Structural differences in kidney hilar, medullary and cortical vasculature reflected unique functional adaptations of each zone. This work represents the first time the arterial vasculature of an intact human kidney has been mapped beyond segmental arteries, potentiating novel computational models of kidney vascular flow in humans. Our analyses have implications for understanding how blood vessel structure collectively scales to facilitate specialised functions in human organs.