1. Department of Gastroenterology, Hepatology and Endocrinology, Medizinische Hochschule Hannover, Hannover, Germany
2. Institute of Diagnostic and Interventional Radiology and Neuroradiology, Klinikum Bogenhausen, Munich, Germany
3. Department of Internal Medicine 2, Caritas-Krankenhaus Bad Mergentheim, Germany
4. Department of Radiology; Stanford University; Stanford, CA, USA