Cortical Disarray Measurement in Mild Cognitive Impairment and Alzheimer's Disease

This is a multi-centre observational longitudinal cohort study to evaluate and optimise the Cortical Disarray Measurement (CDM) technique for diagnosis and prognosis in patients with mild cognitive impairment and prodromal / mild Alzheimer's Disease. CDM is a novel MRI analysis tool that quantifies cortical and regional diffusion tensor imaging signals in grey matter to observe pathological changes related to neurodegeneration. Participants in this study will be monitored for 2 years. Research Aims: * Assess the accuracy of CDM in detecting progressive change in cognitive and functional measures over 2 years in participants presenting with mild cognitive impairment or early dementia. * Determine the relationship between CDM (both cross-sectionally and longitudinally) and change on standard cognitive and functional assessment measures. * Explore patient and companion views and experiences of the diagnostic journey for dementia and their views on CDM implementation. * To explore the costs and consequences of introducing CDM-augmented MRI as a form of early diagnosis of Alzheimer's disease in people presenting with MCI or mild AD compared to current practice.