Longitudinal Imaging Biomarkers of Disease Progression in DLB

Inclusion Criteria: * Diagnosis of probable DLB, at least 18 years of age, reliable informant who personally speaks with or sees the participant at least weekly, sufficiently fluent in English, must be willing and able to consent to the protocol and undergo up to 6 visits over 5 years, willing and able to undergo neuropsychological testing and no contraindication to MRI imaging. Exclusion Criteria: * Presence of another neurologic disorder which could impact findings, such as multiple sclerosis, brain tumors, etc., unwilling to return for follow-up yearly and undergo neuropsychological testing and MR imaging, if undergoing Tau imaging cannot have QT Prolongation, do not have a reliable informant.