2Turner J, Wilde CH, Hughes K, et al. Ultrasound - guided retrieval of small foreign objects in subcutaneous tissue [J]. Ann Emerg Med,1997,29(6) :731.
3Cinsberg MJ, Ellis CL, Flom LL. Detection of soft tissue foreign bodies by plain radiography, xerography, computed tomography, and uhrasonography[J]. Ann Emerg Med, 1990,19 (6) :701.
