1. Department of Medical Ultrasonics, The Third Affiliated Hospital of Sun Yat-sen University, 600 Tianhe Rd, Tianhe District, Guangzhou, Guangdong Province, China, 510630.
2. Department of Medical Ultrasonics, Henan Provincial People's Hospital, Zhengzhou, Henan Province, China.
3. Department of Medical Ultrasonics, The First People's Hospital of Foshan, Foshan, Guangdong Province, China.