1. From the Department of Medical Imaging, Peter Munk Cardiac Centre (F.S.T., P.T., K.H.), Division of Cardiology, Peter Munk Cardiac Centre (P.T., J.A.U.), and Department of Laboratory Medicine & Pathobiology (M.A.S.), Toronto General Hospital, University Health Network, University of Toronto, 585 University Ave, 1 PMB-298, Toronto, ON, Canada M5G 2N2; and Department of Medical Imaging (K.H.) and Cardiovascular Division (J.A.U.), Women’s College Hospital, University of Toronto, Toronto, Canada).