A Study to Evaluate the Diagnostic Efficacy of DaTSCAN™ Ioflupane (123I) Injection in Single Photon Emission Computed Tomography (SPECT) for the Diagnosis of Parkinsonian Syndrome (PS) in Chinese Patients

Inclusion Criteria: For all participants:

1. Chinese male or female, aged 40 to 80 years, has agreed to sign and date the writteninformed consent form. For Healthy Volunteers:
2. Non-patient volunteers with good age-appropriate health as established by clinicalexamination during screening and no evidence of movement disorder by completeneurological evaluation. For participants with Parkinson's disease:
3. A diagnosis of clinically established or clinically probable PD in accordance with theMovement Disorder Society (MDS) Clinical Diagnostic Criteria for Parkinson's Disease. For participants with MSA (SDD):
4. A diagnosis of probable or possible MSA in accordance with the Second ConsensusStatement on the Diagnosis of MSA. For participants with PSP (SDD):
5. A diagnosis of probable or possible PSP in accordance with the Clinical Criteria forthe Diagnosis of Progressive Supranuclear Palsy National Institute for NeurologicalDisorders and Society for PSP (NINDS-SPSP) For participants with ET (no SDD):
6. A diagnosis of definite or probable ET in accordance with the WashingtonHeights-Inwood Genetic Study of Essential Tremor (WHIGET) diagnostic criteria for ET (no SDD) .

Exclusion Criteria:

1. The participant is lactating.
2. The participant is pregnant as detected by a β-human chorionic gonadotropin (β-hCG)pregnancy test.
3. A cerebral structural vascular abnormality indicative of at least 1 infarction in theregion of the basal ganglia (including the internal capsule) ≥5 mm has been confirmed,preferably by magnetic resonance imaging (MRI) performed within 6 months of screening.If an MRI is not clinically feasible, cerebral CT imaging within 6 months is alsoacceptable.
4. The participant is diagnosed with major neurocognitive disorder by the Diagnostic andStatistical Manual of Mental Disorders (DSM) 5 criteria, or Mini-Mental StateExamination total score is <24.
5. Participant is being investigated for or has been diagnosed and/or is being treatedfor repeated stroke with stepwise progression of Parkinson features.
6. History of repeated head injury (≥3 concussions, or history of professional sportswith repeated head trauma [e.g., boxing]).
7. History of definite encephalitis (≥1 episode of confirmed encephalitis with objectiveresidual neurologic deficit).
8. The participant is using or has insufficient washout from medication known orsuspected to interact with striatal uptake through direct competition with binding ofDaTSCAN™ to the dopamine transporters (i.e., amphetamine, benztropine, bupropion,cocaine, mazindol, methylphenidate, phentermine, sertraline, selective serotoninreuptake inhibitors) before the imaging visit.
9. The participant is using Chinese traditional medicine for PD treatment, which cannotbe safely withdrawn for at least 1 week (7 days) before the imaging visit.
10. The participant has a moderate to severe renal impairment (e.g., serum creatinine >1.5x upper limit of normal [ULN], blood urea nitrogen [BUN] >30 mg/dL).
11. The participant has a moderate to severe hepatic impairment (bilirubin >2x ULN andalanine aminotransferase (ALT) or aspartate aminotransferase (AST)>3x ULN).
12. The participant has a history of current abuse of drugs and/or alcohol (for theprevious 12 months before trial enrolment).
13. The participant has a history of occupational exposure to any radiation >50millisievert/year (mSv/year).
14. The participant has been previously enrolled in this study or participated in aclinical study involving an investigational pharmaceutical product within 30 daysprior to screening and/or any radiopharmaceutical within a minimum of 5 radioactivehalf-lives prior to screening.
15. The participant presents with symptoms suggestive of corticobasal degeneration orHuntington's disease.
16. The participant has known allergies to the investigational medicinal product (IMP).
17. The participant presents with any clinically active, serious, life-threatening diseasewith a life expectancy of less than 12 months.
18. Any laboratory value(s) exceeding the limits of normality if deemed to be clinicallyrelevant by the investigator.
19. The participant complains of claustrophobia.
20. The participant has a moderate to severe thyroid disease (thyroid stimulating hormone [TSH] exceeding the limits of normality by more than 10%), if deemed to be clinicallyrelevant by the investigator. For participants with ET:
21. The participant has at least 1 first-degree relative diagnosed with PD. For Healthy Volunteers:
22. History of psychiatric illness. For all participants:
23. It is the physician's best judgment not to include the participant in the trial.