title: Computed tomographic virtual colonoscopy computer-aided polyp detection in a screening population.
abstract: OBJECTIVE
  The sensitivity of computed tomographic (CT) virtual colonoscopy (CT colonography) for detecting polyps varies widely in recently reported large clinical trials. Our objective was to determine whether a computer program is as sensitive as optical colonoscopy for the detection of adenomatous colonic polyps on CT virtual colonoscopy.
  
  
  METHODS
  The data set was a cohort of 1186 screening patients at 3 medical centers. All patients underwent same-day virtual and optical colonoscopy. Our enhanced gold standard combined segmental unblinded optical colonoscopy and retrospective identification of precise polyp locations. The data were randomized into separate training (n = 394) and test (n = 792) sets for analysis by a computer-aided polyp detection (CAD) program.
  
  
  RESULTS
  For the test set, per-polyp and per-patient sensitivities for CAD were both 89.3% (25/28; 95% confidence interval, 71.8%-97.7%) for detecting retrospectively identifiable adenomatous polyps at least 1 cm in size. The false-positive rate was 2.1 (95% confidence interval, 2.0-2.2) false polyps per patient. Both carcinomas were detected by CAD at a false-positive rate of 0.7 per patient; only 1 of 2 was detected by optical colonoscopy before segmental unblinding. At both 8-mm and 10-mm adenoma size thresholds, the per-patient sensitivities of CAD were not significantly different from those of optical colonoscopy before segmental unblinding.
  
  
  CONCLUSIONS
  The per-patient sensitivity of CT virtual colonoscopy CAD in an asymptomatic screening population is comparable to that of optical colonoscopy for adenomas > or = 8 mm and is generalizable to new CT virtual colonoscopy data.
authors.affiliation: Diagnostic Radiology Department, Warren Grant Magnuson Clinical Center, National Institutes of Health, Bethesda, Maryland 20892-1182, USA. rms@nih.gov
authors.forename: Ronald M
authors.initials: RM
authors.lastname: Summers
authors.forename: Jianhua
authors.initials: J
authors.lastname: Yao
authors.forename: Perry J
authors.initials: PJ
authors.lastname: Pickhardt
authors.forename: Marek
authors.initials: M
authors.lastname: Franaszek
authors.forename: Ingmar
authors.initials: I
authors.lastname: Bitter
authors.forename: Daniel
authors.initials: D
authors.lastname: Brickman
authors.forename: Vamsi
authors.initials: V
authors.lastname: Krishna
authors.forename: J Richard
authors.initials: JR
authors.lastname: Choi
mesh_terms: D018256:Adenomatous Polyps / Q000175:diagnosis* / Q000473:pathology; D000328:Adult; D000368:Aged; D015331:Cohort Studies; D003111:Colonic Polyps / Q000175:diagnosis* / Q000473:pathology; D023881:Colonography, Computed Tomographic; D003936:Diagnosis, Computer-Assisted; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D021621:Imaging, Three-Dimensional; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D012372:ROC Curve; D011897:Random Allocation; D012680:Sensitivity and Specificity