Fig. 4.

Comparison of model fits to the patient data. (A) Example concentration–time curve for normal-appearing white matter in a single patient. In general, the steady-state model does not fit the data well; while both the Patlak and modified Tofts (mTofts) models typically fit the data similarly well, the Patlak model has a higher Akaike weight (AW) than the modified Tofts model in most cases due to the lower number of free parameters. (B) Comparison of AW for the three models in normal-appearing white matter (NAWM), white matter hyperintensities (WMH), deep grey matter (DGM) and recent stroke lesions (RSL). In most patients, the Patlak model had the highest AW for all tissue types (legend as in A).