Participants
Eleven participants including five untreated patients diagnosed as PD (PD group) and six healthy volunteers as controls (HC group) underwent [11C]CFT total-body PET/CT scans in our department from January to December 2021. The neurologic assessment for patients including the third part of Unified Parkinson Disease Rating Scale (UPDRS III), modified Hoehn and Yahr stage (mH-Y), and Non-motor Symptoms Scale (NMSS) were recorded. The detailed characteristics of all participants were listed in Table 1 . Healthy volunteers were sourced from health screening participants with no history of significant medical, neuropsychiatric illnesses, or neoplastic diseases, which were excluded using [18F]FDG PET/CT. This retrospective study followed the principles of the Declaration of Helsinki and has been approved by the ethics committee of Renji Hospital with written informed consent waived.