Pancreatic cancer accounts for about 3% of all cancer-related deaths in the US. An elevation of interstitial fluid pressure (IFP) is a major barrier to drug delivery in solid tumors. Noninvasive estimation of IFP as a biomarker in typically inaccessible tumors is a significant step toward assessing tumor response to therapy. We applied well-recognized fluid flow in porous media to mouse models of pancreatic ductal adenocarcinoma DCE-MRI data using extended Tofts' model-derived permeability maps with tumor-appropriate tumor geometry. Initial results suggest that after validation, IFP can be imaging biomarkers of early response to therapy.