1. Ultrasound Center, The Affiliated Hospital of Guizhou Medical University, Guiyang, China;
2. Department of Ultrasound, The Peoplés Hospital of QIANNAN, Duyun, Guizhou, China;
3. Department of Thyroid Surgery, The Affiliated Hospital of Guizhou Medical University, Guiyang, China;
4. Department of Ultrasound, First Affiliated Hospital of Guangxi Medical University, Nanning, China