Please assess the completion status of the following clinical trial:

Trial Title: Imaging Biomarkers of Progression of Mobility Impairment in Parkinson Disease

Study Design Characteristics:
- Allocation: None
- Intervention Model: None
- Observational Model: COHORT
- Primary Purpose: None
- Time Perspective: PROSPECTIVE
- Masking: None
- Phase: None
- Number of Arms: None

Eligibility Criteria:
Inclusion Criteria:~* Patients who meet the UK Parkinson's Disease Society Brain Bank Research Center clinical diagnostic criteria for PD.~* Hoehn and Yahr stages 1-2.5 at initial recruitment in baseline study.~* Absence of dementia confirmed by neuropsychological testing at initial recruitment in baseline study.~Exclusion Criteria:~* contra-indication for magnetic resonance study~* Pregnancy or breastfeeding

- Gender: ALL
- Minimum Age: 50 Years
- Maximum Age: None
- Healthy Volunteers: t

Study Arms:
- Group 1 Parkinson disease subjects (Type: None): Subjects with Parkinson disease who previously participate in a motor and brain PET (brain positron emission tomography) imaging study who were invited for a longitudinal observational study.

Based on this trial design, predict the completion outcome and termination type (if applicable).