Fig. 4

Average A MDIF and B IDIF curves obtained with their respective SIME approaches (n = 18). Grey-filled area on each graph represents ± one standard deviation. C SIME MDIF (black line) and SIME IDIF (solid grey line) from one representative subject. D WB TAC (solid black line) and E TACs from the six clusters used to obtain the MDIF and IDIF shown in C. The insets present the first 3 min of the respective curves. F Anatomical localization of the clusters whose TACs are shown in E. IDIF: image-derived input function. MDIF: Model-derived input function; TAC: Time-activity curve; GM: Grey matter; SIME: Simultaneous estimation; WB: Whole brain; WM: White matter