1. Mayo Clinic School of Medicine, Mayo Clinic, Rochester, Minnesota
2. Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota
3. Department of Radiology, Mayo Clinic, Rochester, Minnesota
4. Department of Mechanical, Engineering and Bioengineering, University of California, Berkeley, California
5. Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota