1. Department of Ultrasound, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, 107 Yanjiangxi Rd, Guangzhou 510120, China.
2. Department of Nuclear Medicine, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China.
3. Department of Ultrasound, Zengcheng People's Hospital, Guangzhou, China.