1. Division of Geriatrics and General Internal Medicine, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia.
2. Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, Georgia.
3. Department of Neurology, Emory Alzheimer's Disease Research Center, Emory University School of Medicine, Atlanta, Georgia.
4. Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia.