Wide Variations in Cellular-Interstitial Water Exchange Rates are within the Experimental Uncertainty of AIF Variations in their Effect on Uptake Curve Shapes for DCE-MRI Modelling

Matthew R. Orton¹, David J. Collins¹, Martin O. Leach¹

Accurate quantification of DCE-MRI data involves modelling or measurement of three processes: an AIF; transfer of contrast between various compartments; generation of MR signals. Ambiguities between the AIF and the MR signal generation process on tissue curves are investigated. Simulations show that only small AIF changes are needed to account for changes in the signal curves generated by a very wide range of cellular-interstitial water exchange rates. We conclude that the AIF and the MR signal model are strongly coupled very accurate characteristaion of the AIF is needed to have confidence in in-vivo estimates of cellular-interstitial water exchange rates.