1. From the Department of Radiology, NHS Greater Glasgow & Clyde and Glasgow University, Glasgow Royal Infirmary, 16 Alexandra Parade, Glasgow G31 2ER, Scotland (G.R.); Departments of Medical Physics and Radiology, University of Wisconsin–Madison, Madison, Wis (O.W.); and Department of Radiology, Weill Cornell Medicine, New York, NY (M.R.P., E.M.H.).