1. Department of Nephrology, Peking Union Medical College Hospital, Beijing, China
2. Department of Ultrasound, Peking Union Medical College Hospital, Beijing, China
3. Department of Ultrasound, the First People’s Hospital of Akesu District, Xinjiang, China
4. Department of Ultrasound, the Affiliated Hospital of Jining Medical University, Jining, China
5. Department of Ultrasound, Beijing Pinggu Hospital, Beijing, China
6. Department of Ultrasound, Daqing Oilfield General Hospital, Daqing, China