1. Department of Abdominal Ultrasonography, The First Affiliated Hospital, Harbin Medical University, Harbin 150001, China
2. National Key Laboratory of Science and Technology on Tunable Laser, Harbin Institute of Technology, Harbin 150080, China
3. Institute of Opto-electronics, Harbin Institute of Technology, Harbin 150080, China
4. Department of Pathology, The First Affiliated Hospital, Harbin Medical University, Harbin 150001, China