1. From the Department of Cardiology (D.R., K.P., C.S., W.G.D., S.A.), Institute of Diagnostic Radiology (U.B., K.A., W.B.), and Institute of Medical Physics (S.U.), University of Erlangen-Nürnberg, Germany; Siemens Medical Solutions, Forchheim, Germany (B.O.); and the Department of Radiology, Massachusetts General Hospital, Boston, Mass (S.A.).