TY - JOUR AN - 15 AU - Chen,C.H. AU - Tseng,L.J. AU - Yang,C.C. TI - Preoperative evaluation of periampullary tumors by endoscopic sonography, transabdominal sonography, and computed tomography. JO - J Clin Ultrasound PY - 2001 VL - 29 SP - 313-321 M2 - 313 DO - 10.1002/jcu.1041 ER -