Regional dopaminergic dysfunction patterns discriminate Parkinson’s disease from multiple system atrophy parkinsonian subtype

Highlights • Adaptive probabilistic atlas enables MRI-free 18F-DOPA PET spatial normalization.• Caudate nucleus uptake reduction specific to MSA-P compared to PD.• Cerebellar dopaminergic dysfunction in MSA-P without clinical signs.• Caudate and cerebellar 18F-DOPA uptake differentiate MSA-P from PD.