Abstract. In vivo tracer kinetics, as probed by current tomographic techniques, is revisited from the point of view of fluid kinematics. Proofs of the standard intravascular advective perfusion model from first premises reveal underlying... more
Abstract. In vivo tracer kinetics, as probed by current tomographic techniques, is revisited from the point of view of fluid kinematics. Proofs of the standard intravascular advective perfusion model from first premises reveal underlying assumptions and demonstrate that all single input models apply at best to undefined tube-like systems, not to the ones defined by tomography, i.e. the voxels. In particular, they do not and cannot account for the circulation across them. More generally, it is simply not possible to define a single non-zero steady volumetric flow rate per voxel. Restarting from the fact that kinematics requires the definition of six volumetric flow rates per voxel, one for each face, minimalist, 4D spatiotemporal analytic models of the advective transport of intravascular tracers in the whole organ of interest are obtained. Their many parameters, plasmatic volumetric flow rates and volumes, can be readily estimated at least in some specific cases. Estimates should be...
