From the Department of Diagnostic Radiology, Université de Sherbrooke, Sherbrooke, Canada (M.M.T.); Department of Diagnostic Radiology, Dalhousie University, 1276 S Park St, PO Box 9000, Halifax, NS, Canada B3H 2Y9 (K.E., J.N.B., D.M.); and Department of Radiology, Addenbrooke's Hospital, Cambridge University, Cambridge, England (J.L.B.).