1. From the Department of Academic Radiology (N.A., D.P.A.), University of Nottingham, Queen’s Medical Centre, Nottingham, UK; the Department of Vascular and Endovascular Surgery (N.A., S.T.M.), Queen’s Medical Centre, Nottingham, UK; and the Division of Rehabilitation and Ageing (J.G.), University of Nottingham, Queen’s Medical Centre, Nottingham, UK.