Sampling requirements in DCE-MRI based analysis of high grade gliomas: Simulations and clinical results

Purpose: To investigate the effect of variations in temporal resolution and total measurement times on the estimations of kinetic parameters derived from dynamic contrast-enhanced (DCE) MRI in patients with high-grade gliomas (HGGs). Materials and Methods: DCE-MRI with high temporal resolution (dynamic sampling time (Ts) = 2.1 s and 3.4 s) and total sampling time (Tacq) of 5.2 min was acquired in 101 examinations from 15 patients. Using the modified Tofts model Ktrans, kep ve and vp were estimated. The effects of increasing Ts and reducing Tacq on the estimated kinetic parameters were estimated through down-sampling and data truncation, and the results were compared with numerical simulations. Results: There was an overall dependence of all four kinetic parameters on Ts and Tacq. Increasing Ts resulted in under-estimation of Ktrans and over-estimation of Vp, whereas kep and Ve varied in a less predictable manner. Reducing Tacq resulted in over-estimation of Ktrans and kep and under-estimation of vp and ve. Increasing Ts and reducing Tacq resulted in increased relative error for all four parameters. Conclusion: Estimated Ktrans, Kep, and Ve in HGGs were within 15% of the high sampling rate reference values for Ts<20 s. Increasing Ts and reducing Tacq leads to reduced precision of the estimated values. J. Magn. Reson. Imaging 2013;37:818829. (c) 2012 Wiley Periodicals, Inc.