title: Clinical application of ultrasonic probing for preoperative staging of colorectal carcinoma.
abstract: OBJECTIVE
  The aim of this study was to assess the value of ultrasonic probing (USP) on colonoscopy for the preoperative staging of colorectal carcinoma.
  
  
  METHODS
  Seventy-five patients with colorectal carcinomas proven pathologically underwent USP (Olympus UM-2R, 12 MHz; UM-3R, 20 MHz) on colonoscopy before surgery for colorectal cancer. The results were compared with pathological findings of resected specimens.
  
  
  RESULTS
  Colorectal carcinoma appeared as a hypoechoic mass on USP. USP had an overall accuracy rate of 82.7% for diagnostic T staging of colorectal carcinoma. In determining lymph node metastasis, the sensitivity and specificity were 53.2% and 61.5%, respectively. The positive and negative predictive values were 0.87 and 0.22, respectively.
  
  
  CONCLUSIONS
  USP is valuable for the staging of colorectal carcinoma and has a high accuracy rate for determining the depth of tumour invasion. The preoperative information obtained by this tool may influence the choice of therapy.
authors.affiliation: Department of General Surgery, Zhongshan Hospital, Fudan University, Shanghai, People's Republic of China. pinered@public7.sta.net.cn
authors.forename: Pinghong
authors.initials: P
authors.lastname: Zhou
authors.forename: Liqing
authors.initials: L
authors.lastname: Yao
authors.forename: Guojie
authors.initials: G
authors.lastname: He
authors.forename: Weidong
authors.initials: W
authors.lastname: Gao
authors.forename: Xinyu
authors.initials: X
authors.lastname: Qin
mesh_terms: D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D019160:Endosonography; D008207:Lymphatic Metastasis; D009361:Neoplasm Invasiveness; D012680:Sensitivity and Specificity