title: Preoperative staging of rectal cancer using magnetic resonance imaging with external phase-arrayed coils.
abstract: OBJECTIVE
  Rectal cancer can be accurately staged preoperatively by magnetic resonance imaging (MRI) with external phase-arrayed coils.
  
  
  METHODS
  Comparison of MRIs with pathologic staging.
  
  
  METHODS
  University hospital.
  
  
  METHODS
  Twenty-eight consecutive patients with biopsy-proven rectal cancer who did not undergo irradiation.
  
  
  METHODS
  Patients underwent imaging using a 1.5-T MRI scanner with external phase-arrayed surface coils. Streaking of the perirectal fat and disruption of the bowel wall margin were interpreted as transmural invasion. Lymph nodes were defined as metastatic when they had a diameter of at least 0.5 cm. Tumors were staged according to the TNM staging system (American Joint Committee on Cancer guidelines) as confined to the bowel wall (T1-T2) and invading through the bowel wall (T3-T4). Patients underwent anterior resection (n = 15), abdominoperineal resection (n = 11), or local excision (n = 2).
  
  
  METHODS
  Calculation of sensitivity, specificity, and accuracy for invasion through the bowel wall and lymph node status.
  
  
  RESULTS
  Sensitivity of MRI in detecting invasion through the bowel wall was 89% (16/18), specificity was 80% (8/10), and accuracy was 86% (24/28). Sensitivity for malignant lymphadenopathy was 67% (8/12), specificity was 71% (10/14), and accuracy 69% (18/26).
  
  
  CONCLUSIONS
  Although more costly and not as accurate as endoscopic ultrasound, MRI with phase-arrayed coils had excellent sensitivity at detecting transmural penetration of rectal cancer.
authors.affiliation: Department of Surgical Oncology, School of Medicine, Yale University, 333 Cedar St, New Haven, CT 06520, USA.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Gagliardi
authors.forename: Sancar
authors.initials: S
authors.lastname: Bayar
authors.forename: Robert
authors.initials: R
authors.lastname: Smith
authors.forename: Ronald R
authors.initials: RR
authors.lastname: Salem
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology; D008207:Lymphatic Metastasis; D008279:Magnetic Resonance Imaging / Q000295:instrumentation; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D012004:Rectal Neoplasms / Q000175:diagnosis / Q000473:pathology* / Q000601:surgery; D012007:Rectum / Q000473:pathology*; D012680:Sensitivity and Specificity