1. Department of Radiology, and Divisions of Infectious Diseases and Geriatric Medicine, Department of Internal Medicine, University of Michigan Medical Center, Ann Arbor, Michigan, USA; Department of Radiology, Neuroradiology, Medical University Vienna, Austria; Veterans Affairs Ann Arbor Healthcare System, Ann Arbor, Michigan, USA; Geriatric Research Education and Clinical Center (GRECC), Ann Arbor, Michigan