1. From the Cardiovascular Magnetic Resonance Program, Penn Cardiovascular Institute, and the Noninvasive Imaging Laboratory, Hospital of the University of Pennsylvania, University of Pennsylvania Medical Center, Philadelphia, PA (V.A.F.); Center for Magnetic Resonance and Optical Imaging, Department of Radiology, University of Pennsylvania Medical Center, Philadelphia, PA (W.R.T.W.); and Molecular Imaging Laboratories, Department of Radiology, University of Pennsylvania Medical Center, Philadelphia,...