Introduction

Affiliations

• ¹ Division of Pediatric Imaging, Department of Radiology, Massachusetts General Hospital, 55 Fruit St., Ellison 237, Boston, MA, 02114, USA. msgee@mgh.harvard.edu.
• ² Department of Radiology, Harvard Medical School, Boston, MA, USA. msgee@mgh.harvard.edu.
• ³ Department of Diagnostic Imaging (GBC), The Hospital for Sick Children, Toronto, ON, Canada.
• ⁴ Medical Imaging Department, University of Toronto, Toronto, ON, Canada.