FIGURE 4. Bilateral P/C ratios of ^99mTc-TRODAT-1 in 4 groups. There is preferential involvement of putamen in PD and MSA-P groups, whereas P/C ratios for MSA-C are closer to those of healthy subjects. This indicates relatively diffuse involvement of both putamen and caudate nucleus in MSA-C group. Cont = contralateral; Ipsi = ipsilateral.