1. Department of Pediatrics, Floating Hospital for Children at Tufts Medical Center;
2. Department of Pediatrics, Tufts University School of Medicine, Boston, Massachusetts;
3. Departments of Pediatrics and
4. Department of Pediatrics and Child Health, University of Manitoba; and
5. The Manitoba Institute of Child Health, Winnipeg, Manitoba, Canada
6. Radiology, The Children's Hospital of Philadelphia;
7. Radiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania;