Impact of Precontrast T1 Relaxation Times on DCE-MRI Pharmacokinetic Parameters: T1 Mapping Versus a Fixed Reference Value

Tobias Heye¹, Daniel T. Boll¹, Mustafa Bashir¹, Elmar M. Merkle¹

DCE-MRI pharmacokinetic parameter (Ktrans, Kep, Ve, iAUGC) calculation requires the T1 relaxation time (RT) of the tissue to convert signal intensity into a gadolinium concentration. Commercially available DCE-MRI post-processing software allow T1-RT measurement by variable flip angle sequences or input of a reference value. This study assesses the differences between calculations by both methods in 15 DCE-MRI cases. Additionally the behavior of pharmacokinetic parameters with changing T1-RT is measured. There is a considerable difference (6.6-54.9%) between calculations using T1-RT measurement vs. a reference value. Increasing T1-RT yield lower pharmacokinetic parameter values within the same DCE-MRI data set.