[1] Sun Yat Sen Univ, Dept Med Ultrason, Affiliated Hosp 3, Inst Diagnost & Intervent Ultrasound, Guangzhou 510630, Guangdong, Peoples R China
[2] Sun Yat Sen Univ, Affiliated Hosp 6, Dept Med Ultrason, Guangzhou 510630, Guangdong, Peoples R China
[3] Sun Yat Sen Univ, Inst Diagnost & Intervent Ultrasound, Affiliated Hosp 1, Dept Hepatobiliary Surg, Guangzhou 510080, Guangdong, Peoples R China
[4] Sun Yat Sen Univ, Inst Diagnost & Intervent Ultrasound, Affiliated Hosp 1, Dept Med Ultrason, Guangzhou 510080, Guangdong, Peoples R China