1. Department of Ultrasound, Zhongshan Hospital, Fudan University, Shanghai, China
2. Department General Internal Medicine, Hirslanden Clinics Beau-Site, Salem and Permancence, Bern, Switzerland
3. Department of Radiology, University Medical Center Regensburg, Regensburg, Germany
4. Department of Medicine, Teaching Hospital General Medicine Lindenhofgruppe, Berne, Switzerland