title: Diagnostic performance of computed tomography colonography and colonoscopy: a prospective and validated analysis of 231 paired examinations.
abstract: BACKGROUND
  Detection of colorectal tumors with computed tomography colonography (CTC) is an alternative to conventional colonoscopy (CC), and clarification of the diagnostic performance is essential for cost-effective use of both technologies.
  
  
  OBJECTIVE
  To evaluate the diagnostic performance of CTC compared with CC.
  
  
  METHODS
  231 consecutive CTCs were performed prior to same-day scheduled CC. The radiologist and endoscopists were blinded to each other's findings. Patients underwent a polyethylene glycol bowel preparation, and were scanned in prone and supine positions using a single-detector helical CT scanner and commercially available software for image analysis. Findings were validated (matched) in an unblinded comparison with video-recordings of the CCs and re-CCs in cases of doubt.
  
  
  RESULTS
  For patients with polyps >/=5 mm and >/=10 mm, the sensitivity was 69% (95% CI 58-80%) and 81% (68-94%), and the specificity was 91% (84-98%) and 98% (93-100%), respectively. For detection of polyps >/=5 mm and >/=10 mm, the sensitivity was 66% (57-75%) and 77% (65-89%). A flat, elevated low-grade carcinoma was missed by CTC. One cancer relapse was missed by CC, and a cecal cancer was missed by an incomplete CC and follow-up double-contrast barium enema.
  
  
  CONCLUSIONS
  CC was superior to CTC and should remain first choice for the diagnosis of colorectal polyps. However, for diagnosis of lesions >/=10 mm, CTC and CC should be considered as complementary methods.
authors.affiliation: Department of Surgery and Department of Radiology, Hillerød Hospital, Hillerød, Denmark.
authors.forename: R B
authors.initials: RB
authors.lastname: Arnesen
authors.forename: E
authors.initials: E
authors.lastname: von Benzon
authors.forename: S
authors.initials: S
authors.lastname: Adamsen
authors.forename: L B
authors.initials: LB
authors.lastname: Svendsen
authors.forename: H O
authors.initials: HO
authors.lastname: Raaschou
authors.forename: O Hart
authors.initials: OH
authors.lastname: Hansen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001464:Barium; D003111:Colonic Polyps / Q000000981:diagnostic imaging; D023881:Colonography, Computed Tomographic / Q000191:economics* / Q000379:methods*; D003113:Colonoscopy / Q000191:economics* / Q000379:methods*; D015179:Colorectal Neoplasms / Q000000981:diagnostic imaging* / Q000191:economics; D003287:Contrast Media; D003362:Cost-Benefit Analysis; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media; D001464:Barium