Figure 2.

(a) The shape of ${\text{ROI}}_{\text{MIX}}(\alpha )$ for one of PD subjects (UPDRS 9.0, DD 6, moderate severity) in the DTBZ-MRI ROI space. (b) Contours of ${\text{ROI}}_{\text{MIX}}(\alpha )$ overlaid on the transaxial slices of DTBZ BP_ND images, for two representative PD subjects and three values of α. Arrows point out areas of misalignment between ${\text{ROI}}_{\text{MIX}}(\alpha =1)$ and regions of high activity concentration.