1. National Research Council Canada Institute for Biodiagnostics (Atlantic), Halifax, NS, Canada
2. Department of Radiology of the General Hospital, Tianjin Medical University, Tianjin, China
3. Division of Geriatric Medicine, Department of Medicine, Dalhousie University, Halifax, NS, Canada
4. Departments of Radiology and Neuroscience, Dalhousie University, Halifax, NS, Canada
5. Centre for Health Care of the Elderly, QEII Health Sciences Centre, Halifax, NS, Canada
6. Departments of Medicine (Neurology) and Anatomy and Neurobiology, Dalhousie University, Halifax, NS, Canada
7. Departments of Psychiatry, Dalhousie University, Halifax, NS, Canada