Although stroke is the third leading cause of death in the Western world, clinical advances to identify risk factors for stroke in living patients have been hampered by a lack of noninvasive imaging methods. Cerebral amyloid angiopathy, or CAA, is a major cause of hemorrhagic stroke in western patient populations that affects as many as one third of all people over the age of 75. CAA cannot be diagnosed using any currently existing imaging technology in living patients, and is only detectable by postmortem examination of brain tissue. The long-range goal of our research is to develop a nanotechnology platform that can be used to reliably assess risk of CAA-associated stroke in living patients. These studies represent a powerful proof of concept for the study of hemorrhagic stroke, and will establish a strong scientific framework for the clinical evaluation in humans.