1. Neuroendocrine Unit, Massachusetts General Hospital and Harvard Medical School , Boston, MA 02114 , USA
2. Division of Pediatric Endocrinology, Massachusetts General Hospital for Children and Harvard Medical School , Boston, MA 02114 , USA
3. Department of Radiology, Massachusetts General Hospital, Harvard Medical School , Boston, MA 02114 , USA
4. Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich , Zurich , Switzerland
5. Pediatric Program MGH Weight Center, Massachusetts General Hospital , Boston, MA 02114 , USA