Dynamic contrast-enhanced magnetic resonance imaging parameters independent of baseline T10 values

A baseline T10 value is typically needed for dynamic contrast-enhanced (DCE-) MRI studies. However, an assumed baseline T10 has to be used when T10 measurements for patients are not available. In this work, we systematically investigate the dependence on T10 of the commonly used DCE-MRI parameters (Ktrans, kep, ve and IAUC) as well as several newly defined parameters [the normalized ratios (NRs) of kep, Ktrans and ve, which are measures of relative changes in these parameters between two time points] for a spoiled gradient-echo pulse sequence using simulations and in vivo studies. Effects of various factors on the T10 dependence, such as the true T10 value, flip angle and the potential changes in T10 due to treatment, were also assessed using simulations. We found that DCE-MRI parameters kep and the NR of kep are largely independent of T10, especially when larger flip angles are used (e.g., 30–40°). Their estimations therefore do not require any knowledge of T10. The NRs of Ktrans, ve and IAUC also exhibit independence to T10, but only when T10 remains constant between pre- and posttreatment. The estimation of parameters themselves (Ktrans, ve and IAUC) is highly dependent on the T10 value.