title: [Evaluation of the preoperative staging of rectal cancer by magnetic resonance imaging].
abstract: OBJECTIVE
  To evaluate the value of MRI in preoperative staging of rectal cancer.
  
  
  METHODS
  The data of 156 rectal cancer patients,undergone MRI scans from December 2004 to June 2006 in our hospital, were analyzed retrospectively. Findings of MRI were compared with postoperative pathological examinations.
  
  
  RESULTS
  Intracavitary localized parenchyma tumors were seen in 72 cases, and intestinal wall abnormal incrassation or stricture in other 84 cases from MRI scan. Sixteen cases had rectal polyps simultaneously, 2 cases ovarian cysts, 13 cases anterior-sacral metastases and 2 cases bone metastases. The sensitivity and specificity of T(1-2), T(3) and T(4) rectal cancer by MRI examination were 25%(8/32), 93.3%(84/90), 94.1%(32/34) and 100%(124/124), 57.6%(38/66), 96.7%(118/122) respectively. In MRI imaging, metastatic para-rectal lymph node was diagnosed as the diameter >5 mm or abnormal border or mixed resonance, with a sensitivity of 85.1%(80/94) and specificity of 45.2%(28/62).
  
  
  CONCLUSIONS
  MRI has high accuracy for preoperative staging of rectal cancer, and is useful to detect the serosal infiltration and lymph node metastasis.
authors.affiliation: Department of General Surgery, Colorectal Cancer Research Center, Zhongshan Hospital, Shanghai Medical College, Fudan University, Shanghai 200032, China. xujmin@yahoo.com.cn
authors.forename: Jian-Min
authors.initials: JM
authors.lastname: Xu
authors.forename: Yun-Shi
authors.initials: YS
authors.lastname: Zhong
authors.forename: Meng-Su
authors.initials: MS
authors.lastname: Zeng
authors.forename: Sheng-Xiang
authors.initials: SX
authors.lastname: Rao
authors.forename: Wei-Xin
authors.initials: WX
authors.lastname: Niu
authors.forename: Ye
authors.initials: Y
authors.lastname: Wei
authors.forename: Li
authors.initials: L
authors.lastname: Ren
authors.forename: Xin-Yu
authors.initials: XY
authors.lastname: Qin
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging / Q000379:methods*; D012004:Rectal Neoplasms / Q000473:pathology*; D012189:Retrospective Studies; D055815:Young Adult