1. From the Departments of Neurology (S.R., J.R., T.S., P.J.L., D.S.) and Radiology (P.V.), Helsinki University Hospital and University of Helsinki, Finland; Department of Clinical Therapeutics (G.G.), National and Kapodistrian University of Athens, Greece; School of Biomedical Engineering and Imaging Sciences (G.G.), King's College London; and Institute of Cardiovascular Science (G.G.), University College London, United Kingdom.