1. Department of Internal Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
2. Division of Gastroenterology and Hepatology, Northwestern University, Chicago, Illinois, USA
3. University of Pittsburgh School of Medicine, Pennsylvania, USA
4. Division of Gastroenterology, Hepatology and Nutrition, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
5. Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
6. Department of Pathology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
7. Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA