title: Colonic polyps: application value of computer-aided detection in computed tomographic colonography.
abstract: BACKGROUND
  Colonic polyps are frequently encountered in clinics. Computed tomographic colonography (CTC), as a painless and quick detection, has high values in clinics. In this study, we evaluated the application value of computer-aided detection (CAD) in CTC detection of colonic polyps in the Chinese population.
  
  
  METHODS
  CTC was performed with a GE 64-row multidetector computed tomography (MDCT) scanner. Data of 50 CTC patients (39 patients positive for at least one polyp of ≥ 0.5 cm in size and the other 11 patients negative by endoscopic detection) were retrospectively reviewed first without computer-aided detection (CAD) and then with CAD by four radiologists (two were experienced and another two inexperienced) blinded to colonoscopy findings. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of detected colonic polyps, as well as the areas under the ROC curves (Az value) with and without CAD were calculated.
  
  
  RESULTS
  CAD increased the overall sensitivity, specificity, positive predictive value, negative predictive value and accuracy of the colonic polyps detected by experienced and inexperienced readers. The sensitivity in detecting small polyps (5 - 9 mm) with CAD in experienced and inexperienced readers increased from 82% and 44% to 93% and 82%, respectively (P > 0.05 and P < 0.001). With the use of CAD, the overall false positive rate and false negative rate for the detection of polyps by experienced and inexperienced readers decreased in different degrees. Among 13 sessile polyps not detected by CAD, two were ≥ 1.0 cm, eleven were 5 - 9 mm in diameter, and nine were flat-shaped lesions.
  
  
  CONCLUSIONS
  The application of CAD in combination with CTC can increase the ability to detect colonic polyps, particularly for inexperienced readers. However, CAD is of limited value for the detection of flat polyps.
authors.affiliation: Department of Radiology, China-Japan Union Hospital, Jilin University, Changchun, Jilin 130000, China.
authors.forename: Hui-Mao
authors.initials: HM
authors.lastname: Zhang
authors.forename: Wei
authors.initials: W
authors.lastname: Guo
authors.forename: Gui-Feng
authors.initials: GF
authors.lastname: Liu
authors.forename: Dong-Hong
authors.initials: DH
authors.lastname: An
authors.forename: Shuo-Hui
authors.initials: SH
authors.lastname: Gao
authors.forename: Li-Bo
authors.initials: LB
authors.lastname: Sun
authors.forename: Hai-Shan
authors.initials: HS
authors.lastname: Yang
mesh_terms: D000328:Adult; D000368:Aged; D003111:Colonic Polyps / Q000175:diagnosis* / Q000000981:diagnostic imaging*; D023881:Colonography, Computed Tomographic / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D055815:Young Adult