1. Department of Radiology, Division of Abdominal Imaging, Massachusetts General Hospital, 55 Fruit St, White 270, Boston, MA 02114.
2. Harvard Medical School, Boston, MA.
3. Department of Radiology, Division of Nuclear Radiology, Massachusetts General Hospital, Boston, MA.
4. Department of Medicine, St Elizabeth's Medical Center, Tufts University School of Medicine, Boston, MA.
5. Department of Radiology, Massachusetts General Hospital, Boston, MA.
6. Department of Radiology, Division of Thoracic Imaging and Intervention, Massachusetts General Hospital, Boston, MA.