**Targeted Α-synuclein PET Imaging in the Diagnosis of Multiple System Atrophy** *Multiple System Atrophy (MSA)* is a rare brain disorder that affects movement, balance, and the body's automatic functions. This study aims to use a special imaging technique called *α-synuclein (alpha-syn) PET* to look at the levels and location of a protein called α-synuclein in the brains of people with MSA. This can help doctors understand how severe the disease is and how it might progress. **Key Points:** - **Study Duration and Visits:** Participants will need to visit for imaging tests; the exact number of visits isn't specified. - **Eligibility:** You need to be over 35 and have a confirmed or probable diagnosis of MSA. Pregnant or breastfeeding individuals cannot participate. - **Compensation:** The study does not specify if there is any payment or compensation for participation. Participants must not have certain other brain conditions or a history of substance abuse. The imaging techniques used are non-invasive, but you must be able to undergo MRI and PET scans. This study could help improve MSA diagnosis and treatment in the future.