a Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, MD b Department of Medicine (Cardiology Division), Massachusetts General Hospital, Harvard Medical School, Boston, MA c Department of Medicine (Division of Cardiology), University of Rochester Medical Center, Rochester, NY d Department of Cardiology, Sismanoglio Hospital, Athens, Greece e Division of Cardiovascular Disease, Department of Medicine, University of Alabama at Birmingham and Birmingham Veterans Affairs Medical Center, Birmingham, AL f Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD g Departments of Medicine (Division of Cardiology) and Imaging Sciences (Nuclear Medicine), University of Rochester Medical Center, Rochester, NY