ABSTRACT ? BIOMARKER/NEUROIMAGING CORE The overall goal of the proposed Biomarker/Neuroimaging Core in the Rush Alzheimer?s Disease Research Center (Rush ADRC) is to build a resource of neuroimaging data on participants of the Rush ADRC and ancillary studies, and provide neuroimaging expertise to facilitate high quality, cutting edge, externally funded research focusing on the transition from normal aging to mild cognitive impairment (MCI) to the earliest stages of Alzheimer?s disease (AD) and other dementias. Specifically, the Biomarker/Neuroimaging Core will integrate high quality, multi-modal, longitudinal in-vivo and ex-vivo brain magnetic resonance imaging (MRI) data and newly collected positron emission tomography (PET) data from participants of the Rush ADRC and separately funded studies, all based on state-of-the-art, uniform data acquisition protocols. The Biomarker/Neuroimaging Core will perform thorough quality checks and detailed processing of the in-vivo and ex-vivo MRI data in the database to generate rich output on macro-structural, micro-structural, chemical, and functional brain characteristics and on novel classifiers of vascular and neurodegenerative processes in the older adult brain. Quality checks and processing of the PET data will be conducted by SCAN (Standardized Centralized Alzheimer?s and Related Dementias Neuroimaging). The Biomarker/Neuroimaging Core of the Rush ADRC will widely distribute all brain MRI and PET data and processing results to investigators within and outside of the Rush ADRC, and will provide neuroimaging expertise in support of research efforts in normal aging, cognitive decline, mild cognitive impairment, AD and related dementias. The proposed Biomarker/Neuroimaging Core will build upon strengths of the Rush ADRC including A) longitudinal clinical assessment of persons who enroll without dementia, B) longitudinal ante-mortem biofluid collection, and C) post-mortem biospecimen collection from large numbers of persons, many without dementia. The contributions of the Biomarker/Neuroimaging Core will stimulate research that A) develops novel MRI-based classifiers of age-related neuropathologies, B) elucidates brain mechanisms supporting cognitive and motor health or leading to decline, C) evaluates the effects of risk factors on the brain, D) links neuroimaging to multi-level omics, E) supports the development and validation of novel biomarkers based on peripheral blood and retinal imaging, and F) ascertains the role of various brain characteristics in racial/ethnic disparities of cognitive aging related outcomes.