Schematic diagrams of the compartment models. In the upper diagram, a standard single-tissue compartment (1T2k) is shown. In this study, two different implementations were used: the 1T2k60 model using 60 min of data acquisition and the 1T2k10 model using the first 10 min of data acquisition. In the lower diagram a standard two-tissue compartment (2T4k) model is shown. In this study, two different implementations were used: the 2T4k model without and the 2T4kVTnsfix model with fixation of K
2 to the whole brain grey matter value. C, compartment.