1. Department of Ultrasound, The First Affiliated Hospital of Dalian Medical University, Liaoning, Dalian, P.R. China;
2. Department of General Surgery, The First Affiliated Hospital of Dalian Medical University, Liaoning, Dalian, P.R. China;
3. Center of Genome and Personalized Medicine, Institute of Cancer Stem Cell, Dalian Medical University, Liaoning, Dalian, P. R. China