1. Department of Central Laboratory, Affiliated Hospital of Jining Medical University, Jining, Shandong 272029, P.R. China
2. Department of Neurosurgery, Affiliated Hospital of Jining Medical University, Jining, Shandong 272029, P.R. China
3. Department of Orthopaedic Surgery, Orthopaedic Research Labs, University of Virginia, Charlottesville, VA 22908, USA
4. Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA 22908, USA