title: Transabdominal ultrasonography in preoperative staging of gastric cancer.
abstract: OBJECTIVE
  To investigate the value of transabdominal ultrasonography (US) in the preoperative staging of gastric cancer.
  
  
  METHODS
  A total of 198 patients with gastric cancer underwent preoperatively transabdominal US, depth of tumor infiltration was assessed in 125 patients, and lymph node metastasis was assessed in 106 patients.
  
  
  RESULTS
  The staging accuracy of transabdominal US was 55.6%, 75.0%, 87.3% and 71.1% in T1, T2, T3 and T4 carcinomas, respectively. The overall accuracy was 77.6%. The detection rate for pancreatic invasion and liver invasion was 77.4%, 71.4%, respectively. The sensitivity, specificity, accuracy of transabdominal US in assessment of lymph node metastasis were 77.6%, 64.1%, 72.6%, respectively. Various shapes such as round, ovoid, spindle were encountered in benign and malignant lymph nodes. Majority of both benign and malignant lymph nodes were hyperechoic and had a distinct border. Benign lymph nodes were smaller than malignant lymph nodes in length and width (P = 0.000, 0.005). Irregular shape, fusional shape, infiltrative signs, inhomogenous echo were seen mainly in malignant lymph nodes (P = 0.045, 0.006, 0.027, 0.006).
  
  
  CONCLUSIONS
  Transabdominal US is useful for preoperative staging in gastric cancer, although it is difficult to differentiate benign from malignant lymph nodes.
authors.affiliation: Department of Ultrasonography, School of Oncology, Peking University, Beijing 10036, China.
authors.forename: Sheng-Ri
authors.initials: SR
authors.lastname: Liao
authors.forename: Ying
authors.initials: Y
authors.lastname: Dai
authors.forename: Ling
authors.initials: L
authors.lastname: Huo
authors.forename: Kun
authors.initials: K
authors.lastname: Yan
authors.forename: Lin
authors.initials: L
authors.lastname: Zhang
authors.forename: Hui
authors.initials: H
authors.lastname: Zhang
authors.forename: Wen
authors.initials: W
authors.lastname: Gao
authors.forename: Min-Hua
authors.initials: MH
authors.lastname: Chen
mesh_terms: D000005:Abdomen; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000000981:diagnostic imaging; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging / Q000379:methods* / Q000592:standards; D011300:Preoperative Care; D015203:Reproducibility of Results; D013274:Stomach Neoplasms / Q000000981:diagnostic imaging* / Q000556:secondary* / Q000601:surgery; D014463:Ultrasonography