The influence of temporal resolution in determining pharmacokinetic parameters from DCE-MRI data

Abstract

We investigated the influence of the temporal resolution of dynamic contrast-enhanced MRI data on pharmacokinetic parameter estimation. Dynamic Gd-DTPA (Gadolinium-diethylene triamine pentaacetic acid) enhanced MRI data of implanted prostate tumors on rat hind limb were acquired at 4.7 T, with a temporal resolution of ∼5 sec. The data were subsequently downsampled to temporal resolutions in the range of 15 sec to 85 sec, using a strategy that involves a recombination of k-space data. A basic two-compartment model was fit to the contrast agent uptake curves. The results demonstrated that as temporal resolution decreases, the volume transfer constant (Ktrans) is progressively underestimated (∼4% to ∼25%), and the fractional extravascular extracellular space (ve) is progressively overestimated (∼1% to ∼10%). The proposed downsampling strategy simulates the influence of temporal resolution more realistically than simply downsampling by removing samples. © 2010 Wiley-Liss, Inc.