On the a priori identifiability of the two-compartment distributed parameter model from residual tracer data acquired by dynamic contrast-enhanced imaging.

Tracer kinetics models are commonly employed to estimate physiological parameters related to blood transport and capillary-tissue exchange. A priori identifiability addresses the question of whether the parameters in a model can be uniquely determined from a given experiment. It has been previously shown that the one- and two-compartment distributed parameter (DP) models are nonidentifiable from tracer outflow data obtained by arterial-venous sampling. In this correspondence, we show that both DP models are a priori identifiable from residual tracer data obtained by dynamic contrast-enhanced (DCE) imaging. We list the various parameters of the DP models that can be uniquely estimated from DCE imaging data, and discuss this seemingly different outcome for DCE imaging experiments, as compared with the arterial-venous sampling experiments.