Rachel A. Powsner, MD, Director of Nuclear Medicine Section, Department of Radiology, Boston Veterans Administration Healthcare System, and Clinical Professor of Radiology, Boston University School of Medicine, Boston, MA, USA. Matthew R. Palmer, PhD, Director of Medical Imaging Physics, Department of Radiology, Beth Israel Deaconess Medical Center, and Assistant Professor of Radiology, Harvard Medical School, Boston, MA, USA. Edward R. Powsner, MD, Former Chief, Nuclear Medicine Service Veterans Administration Hospital, Allen Park, MI, USA, and Former Professor and Associate Chairman, Department of Pathology, Michigan State University, East Lansing, MI, USA.