title: Comparison of the accuracy of CT colonography and colonoscopy in the diagnosis of colorectal cancer.
abstract: OBJECTIVE
  The available evidence was reviewed to compare the effectiveness of CT colonography with that of colonoscopy for colorectal cancer (CRC) screening.
  
  
  METHODS
  An electronic search was conducted using PubMed, EMBASE, the Cochrane Library and Centre for Reviews and Dissemination databases, from inception to July 2009. Studies were included if investigations used CT colonography for CRC screening in asymptomatic populations. Studies were excluded if investigations were conducted for the diagnosis of CRC or in elderly, high-risk or symptomatic populations.
  
  
  RESULTS
  Of the 213 references identified, nine studies were included. The specificity of CT colonography in screening for CRC was high, although it decreased with decreasing diameter of polyp to be detected. The sensitivity of CT colonography for the detection of polyps < 6 mm in diameter was low and heterogeneous, although it was higher for polyps > 10 mm. The main factors contributing to a greater sensitivity of CT colonography were the inclusion of only populations with an average CRC risk and colonic insufflation with CO2 . The incidence of adverse effects was very low for both tests.
  
  
  CONCLUSIONS
  CT colonography has high specificity but heterogeneous sensitivity, although in most cases it is not as sensitive or specific as conventional colonoscopy. CT colonography could therefore be useful as a screening test for populations with an average risk of CRC.
authors.affiliation: Andalusian Health Technology Assessment (AETSA), Seville, Spain.
authors.forename: J E
authors.initials: JE
authors.lastname: Martín-López
authors.forename: C
authors.initials: C
authors.lastname: Beltrán-Calvo
authors.forename: R
authors.initials: R
authors.lastname: Rodríguez-López
authors.forename: T
authors.initials: T
authors.lastname: Molina-López
mesh_terms: D000236:Adenoma / Q000175:diagnosis* / Q000000981:diagnostic imaging; D002277:Carcinoma / Q000175:diagnosis* / Q000000981:diagnostic imaging; D003111:Colonic Polyps / Q000175:diagnosis* / Q000000981:diagnostic imaging; D023881:Colonography, Computed Tomographic; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging; D055088:Early Detection of Cancer / Q000379:methods*; D006801:Humans; D012680:Sensitivity and Specificity
keywords: Colonography; colonoscopy; colorectal neoplasms; computed tomographic; early detection of cancer