1. Department of Medical Imaging, Toronto General Hospital, Peter Munk Cardiac Centre, University Health Network, University of Toronto, 1 PMB-298, 585 University Ave, Toronto, ON M5G 2N2, Canada.
2. Department of Medical Imaging, Clinica Santa Maria, Santiago, Chile.
3. Division of Cardiology, Peter Munk Cardiac Centre, Toronto General Hospital, University Health Network, University of Toronto, Toronto, ON, Canada.
4. Division of Cardiology, Women's College Hospital, University of Toronto, Toronto, ON, Canada.