From the Division of Geriatric Psychiatry & Neuropsychiatry, Dept. of Psychiatry, Johns Hopkins School of Medicine, Baltimore, MD (VR,GSS,UDM,AB,VD); the Division of Epidemiology, Dept. of Health Sciences Research, College of Medicine, Mayo Clinic, Rochester, MN (MM); The Russell H. Morgan Dept. of Radiology and Radiological Sciences, Johns Hopkins University & School of Medicine, Baltimore, MD (XX,DY,MS); and The Image Processing Core, Center for Neuroscience and Regenerative Medicine, NIH/USUHS (DLP).