1. Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts, United States
2. Department of Anesthesia, Critical Care and Pain Medicine, Harvard Medical School, Boston, Massachusetts, United States
3. Department of Medical and Occupational Radiation Protection, Federal Office for Radiation Protection, Salzgitter, Germany
4. Roy J. Carver Department of Biomedical Engineering, University of Iowa, Iowa City, Iowa, United States
5. Disciplina de Pneumologia, Instituto do Coração, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil
6. Electronics Engineering Division, Aeronautics Institute of Technology, Sao Paulo, Brazil
7. Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, Pennsylvania, United States
8. Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts, United States
9. Department of Radiology, Harvard Medical School, Boston, Massachusetts, United States