1. Department of Ultrasound; Shandong Medical Imaging Research Institute, Shandong University; Jinan 250021 P.R. China
2. Department of Histopathology; Shandong Provincial Hospital, Shandong University; Jinan 250021 P.R. China
3. Department of Urology; Shandong Provincial Hospital, Shandong University; Jinan 250021 P.R. China