title: Performance of radiographers in the evaluation of CT colonographic images.
abstract: OBJECTIVE
  The purpose of this study was to compare the accuracy of radiographers with that of radiologists in the interpretation of CT colonographic images.
  
  
  METHODS
  Four observers (a radiologist, a radiologist in training, and two radiographers) evaluated 145 data sets using a primary 3D approach. The radiographers were part of our CT colonography work group and underwent training that consisted of 20 cases. The reference standard was optical colonoscopy with second-look colonoscopy for discrepant lesions > or = 10 mm in diameter. Mean sensitivities per patient and per polyp stratified for size (any size, > or = 6 mm, and > or = 10 mm) was determined for the radiologists and radiographers. Specificity was determined on a per-patient basis.
  
  
  RESULTS
  At colonoscopy in 86 of 145 patients, a total of 317 polyps were found (60 polyps > or = 6 mm in 26 patients and 31 polyps > or = 10 mm in 18 patients). No statistically significant differences were found in detection rates between radiologists and radiographers. Sensitivities for patients with a lesion of any size (66% for radiologists vs 65% for radiographers), > or = 6 mm (81% vs 87%), and > or = 10 mm (both 78%) were similar for all observers. On a per-polyp basis, detection rates were equivalent regardless of polyp size (47% vs 40%), for lesions > or = 6 mm (71% vs 65%), and for lesions > or = 10 mm (69% vs 66%). Mean specificities were similar among patients without lesions (31% vs 30%), patients without lesions > or = 6 mm (71% vs 67%), and patients without lesions > or = 10 mm (93% vs 93%).
  
  
  CONCLUSIONS
  Radiographers with training in CT colonographic evaluation achieved sensitivity and specificity in polyp detection comparable with that of radiologists. Radiographers can be considered reviewers in the evaluation of CT colonographic images.
authors.affiliation: Department of Radiology, Academic Medical Center, Meibergdreef 9, 1105 AZ Amsterdam, Noord-Holland, The Netherlands. s.jensch@amc.uva.nl
authors.forename: Sebastiaan
authors.initials: S
authors.lastname: Jensch
authors.forename: Rogier E
authors.initials: RE
authors.lastname: van Gelder
authors.forename: Jasper
authors.initials: J
authors.lastname: Florie
authors.forename: Marloes A
authors.initials: MA
authors.lastname: Thomassen-de Graaf
authors.forename: Jack V
authors.initials: JV
authors.lastname: Lobé
authors.forename: Patrick M M
authors.initials: PM
authors.lastname: Bossuyt
authors.forename: Shandra
authors.initials: S
authors.lastname: Bipat
authors.forename: C Yung
authors.initials: CY
authors.lastname: Nio
authors.forename: Jaap
authors.initials: J
authors.lastname: Stoker
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003111:Colonic Polyps / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D023881:Colonography, Computed Tomographic / Q000706:statistics & numerical data*; D003113:Colonoscopy / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009426:Netherlands / Q000453:epidemiology; D015588:Observer Variation; D011361:Professional Competence / Q000706:statistics & numerical data*; D011871:Radiology / Q000706:statistics & numerical data*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013647:Task Performance and Analysis