1College of Computer Science, Xi'an University of Posts and Telecommunications, Xi'an, Shaanxi 710121, PR China
2Department of Radiology, The Second Affiliated Hospital of Medical College, Xi'an Jiaotong University, Xi'an, Shaanxi 710004, PR China
3Department of Bone and Joint Surgery, The Second Affiliated Hospital of Medical College, Xi'an Jiaotong University, Xi'an, Shaanxi 710004, PR China