Multiexponential and multicompartmental approaches for analysis of tracer washout data from animal.

A comparison is made between multiexponential and multicompartmental analyses of tracer washout data from biological tissues. Various analytical and computer methods are used to explore the relations between kinetic parameters of three-compartment models and parameters of three-exponential functions fitted to typical observed tracer washout records and also to examine relations between kinetic parameters of the same three-compartment models determined analytically and numerically. It is concluded that exponential factors and coefficients cannot always be equated respectively with conpartmental transport rate constants or compartment sizes. Sufficient analytical and computer methodologies exist so that selection of meaningful biological models should not be hampered by a lack of appropriate solution procedures.