The purpose of this study is to evaluate our recently developed MRI reconstruction strategy for producing artifact-free neuro and abdominal MRI data. The new reconstruction strategies, including 1) REKAM and 2) MUSE, are capable of effectively removing motion-related artifacts resulting from global and local motion during neuro and free-breathing abdominal MRI scans, without modifying the MRI pulse sequences and protocols that are currently used in clinical scans. The study team aims to recruit 60 subjects across multiple challenge patient populations: 10 healthy young adults (age 20-30) and 10 healthy older adults (aged 50-70) for abdominal MRI, as well as 20 tremor dominant PD patients and 20 children (age 4-8) for brain MRI scans. There are no known risks in taking MRIs and a unique code will be assigned to each participant to protect their PHI.

Inclusion Criteria:

1. subject's age is within one of the following age ranges (4-8, 20-30, or 50-70 years old);
2. male or female;
3. healthy volunteer or diagnosed with PD ; and
4. devoid of the following exclusion criteria.

Exclusion Criteria:

1. claustrophobia or other MRI contraindications (including pregnancy);
2. diagnosis for dementia (Alzheimer's, Lewy Body, or Vascular);
3. symptomatic psychotic disorders;
4. depression with psychotic symptoms;
5. other psychotic or schizophrenic disorders;
6. recent neuroleptic treatment;
7. history of cardiovascular disease;
8. history of stroke or Transient Ischemic Attack;
9. cancer (other than skin cancer) within the last three years;
10. hospitalization for neurological/psychiatric condition;
11. significant handicaps (e.g., visual or hearing loss, mental retardation) that would interfere with neuropsychological testing or the ability to follow study procedures; or
12. any other factor that in the investigators' judgment may affect patient safety or compliance.

There are 4 separate cohorts of patients. Please see earlier section. 60 subjects will participate in our study.

• 10 healthy younger adult volunteers (ages 20 to 30)
• 10 healthy older adult volunteers (ages 50 to 70) will be recruited for
• 20 tremor-dominant patients with clinically diagnosed Parkinson's disease
• 20 healthy children (4 to 8 y.o.)