Variation in diagnostic performance among radiologists at screening CT colonography

Radiology. 2013 Jul;268(1):127-34. doi: 10.1148/radiol.13121246. Epub 2013 Feb 28.


Purpose: To assess the variation in diagnostic performance among radiologists at screening computed tomographic (CT) colonography.

Materials and methods: In this HIPAA-compliant, institutional review board-approved study, 6866 asymptomatic adults underwent first-time CT colonographic screening at a single center between January 2005 and November 2011. Results of examinations were interpreted by one of eight board-certified abdominal radiologists (mean number of CT colonographic studies per reader, 858; range, 131-2202). Findings at CT colonography and subsequent colonoscopy were recorded, and key measures of diagnostic performance, including adenoma and advanced neoplasia detection rate, were compared among the radiologists.

Results: The overall prevalence of histopathologically confirmed advanced neoplasia was 3.6% and did not differ significantly among radiologists (range, 2.4%-4.4%; P = .067; P = .395 when one outlier was excluded). Overall, 19.5% of polyps detected at CT colonography proved to be advanced neoplasia and did not differ significantly among radiologists (range, 14.4%-23.2%; P = .223). The overall per-polyp endoscopic confirmation rate was 93.5%, ranging from 80.0% to 97.6% among radiologists (P = .585). The overall percentage of nondiagnostic CT colonographic examinations was 0.7% and was consistent among radiologists (range, 0.3%-1.1%; P = .509).

Conclusion: Consistent performance for adenoma and advanced neoplasia detection, as well as other clinically relevant end points, were observed among radiologists at CT colonographic screening.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Chi-Square Distribution
  • Clinical Competence*
  • Colonography, Computed Tomographic*
  • Colonoscopy
  • Colorectal Neoplasms / diagnostic imaging*
  • Colorectal Neoplasms / epidemiology
  • Colorectal Neoplasms / pathology
  • Contrast Media
  • Diatrizoate Meglumine
  • Female
  • Humans
  • Male
  • Middle Aged
  • Observer Variation
  • Prevalence
  • Prospective Studies
  • Regression Analysis
  • Wisconsin / epidemiology


  • Contrast Media
  • Diatrizoate Meglumine