1. Instructor, Department of Anesthesia.
2. Postdoctoral Fellow, Department of Radiology, University Medical Center Nijmegen, Nijmegen, The Netherlands.
3. Laboratory Manager, Kresge Laboratory, Department of Radiology, Children's Hospital.
4. Associate Professor, Department of Radiology.
5. Professor, Departments of Anesthesia and Pediatrics, Harvard Medical School.