Theoretical analysis of blind identification of kinetic parameters in a three compartment model: nonuniqueness problem

Estimation of compartment model parameters can be done in dynamic medical imaging blindly - that is, without an input function. In this work we address the question of uniqueness of blind identification of kinetic parameters for a three compartment model such as is widely used with FDG. We show analytically that if only two regions of interest in the imaged organ are used, the solution is not unique. More regions are shown to lead to a unique solution.