1. Department of Diagnostic Ultrasound for Obstetrics and Gynecology, the Affiliated Hospital of North Sichuan Medical College, Nanchong, Sichuan, China
2. Department of Vascular Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan, China, and Department of Vascular Surgery, Nanchong Centrary Hospital, Nanchong, Sichuan, China
3. Department of Vascular Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan, China