Xiaozhi Zheng1, Ping Ji1 and Jianqun Hu2*
1Department of Ultrasound, The Fourth Affiliated Hospital of Nantong University (The First People’s Hospital of Yancheng), Yancheng 224006, Jiangsu Province, P. R. China.
2Department of Ultrasonic Diagnosis, The First Affiliated Hospital with Nanjing Medical University (Jiangsu Province Hospital), Nanjing 210029, Jiangsu Province, P. R. China.
