The underlying pathophysiological processes of amyloid angiopathy have been difficult to study because the vessel size affected is too smallfor imaging in the human condition, and animal models have not yet been adequately developed or characterized. Herein we present characterization of animal models of overexpression of the human AbetaPP gene, initially developed as models of Alzheimer's disease, but which fortuitously also develop marked cerebral amyloid angiopathy. We also present a novelform of microscopy that allows in vivo imaging of vessels affected by amyloid in the anesthetized, but intact, animal.