1. Department of Ultrasound, The Affiliated Hospital of Qingdao University, Qingdao, China
2. Department of Thyroid Surgery, The Affiliated Hospital of Qingdao University, Qingdao, China
3. Department of Pathology, The Affiliated Hospital of Qingdao University, Qingdao, China
4. Department of Ultrasound, Qilu Hospital of Shandong University, Qingdao, China