Fig. (4) Parametric maps for PIB. Data from the same two experiments as in Fig. (2) were used. The maps show K_acc (left column) and K₁, (right column) for one HC (upper row) and one AD-Hi subject (lower row). For K_acc the colour scale goes from 0.01 to 0.055 min^-1, and for K₁ the scale goes from 0.0 to 0.5 min^-1.