1. Faculdade de Medicina da Universidade de São Paulo; São Paulo Brazil
2. Division of Gastroenterology and GI Endoscopy; University of Malaya; Kuala Lumpur Malaysia
3. Division of Gastroenterology and Hepatology; Department of Medicine; Medical College of Wisconsin; Milwaukee Wisconsin
4. Department of Gastrointestinal Radiation; University of Pennsylvania Medical Center; Philadelphia Pennsylvania
5. Department of Radiology; Perelman School of Medicine at the University of Pennsylvania; Philadelphia Pennsylvania
6. Department of Gastroenterology; Post Graduate Institute of Medical Education and Research; Chandigarh India
7. Endoscopy Unit; Hospital das Clínicas da Faculdade de Medicina da Universdade de São Paulo; São Paulo Brazil