A method to improve reliability of DCE-MRI is presented. It is based on the assumption that neighboring voxels have similar physiological properties. It is formulated as a total variation regularization of the perfusion parameter maps. The method is applied to the adiabatic approximation of the tissue homogeneity model (ATH). Evaluation was done on data of five tumor bearing mice recorded using two contrast agents with different molecular weights. The resulting perfusion parameter maps were more spatially consistent with preserved edges.