title: The effect of computer-aided detection markers on visual search and reader performance during concurrent reading of CT colonography.
abstract: OBJECTIVE
  We aimed to identify the effect of computer-aided detection (CAD) on visual search and performance in CT Colonography (CTC) of inexperienced and experienced readers.
  
  
  METHODS
  Fifteen endoluminal CTC examinations were recorded, each with one polyp, and two videos were generated, one with and one without a CAD mark. Forty-two readers (17 experienced, 25 inexperienced) interpreted the videos during infrared visual search recording. CAD markers and polyps were treated as regions of interest in data processing. This multi-reader, multi-case study was analysed using multilevel modelling.
  
  
  RESULTS
  CAD drew readers' attention to polyps faster, accelerating identification times: median 'time to first pursuit' was 0.48 s (IQR 0.27 to 0.87 s) with CAD, versus 0.58 s (IQR 0.35 to 1.06 s) without. For inexperienced readers, CAD also held visual attention for longer. All visual search metrics used to assess visual gaze behaviour demonstrated statistically significant differences when "with" and "without" CAD were compared. A significant increase in the number of correct polyp identifications across all readers was seen with CAD (74 % without CAD, 87 % with CAD; p < 0.001).
  
  
  CONCLUSIONS
  CAD significantly alters visual search and polyp identification in readers viewing three-dimensional endoluminal CTC. For polyp and CAD marker pursuit times, CAD generally exerted a larger effect on inexperienced readers.
  
  
  CONCLUSIONS
  • Visual gaze is attracted by computer-assisted detection (CAD) marks on polyps • Inexperienced readers' gaze is affected more by CAD than experienced readers. • CAD marks could mean that the unannotated endoluminal surface is relatively neglected. • Correct polyp identification is increased significantly by CAD.
authors.affiliation: Centre for Medical Imaging, University College London, London, UK.
authors.forename: Emma
authors.initials: E
authors.lastname: Helbren
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Fanshawe
authors.forename: Peter
authors.initials: P
authors.lastname: Phillips
authors.forename: Susan
authors.initials: S
authors.lastname: Mallett
authors.forename: Darren
authors.initials: D
authors.lastname: Boone
authors.forename: Alastair
authors.initials: A
authors.lastname: Gale
authors.forename: Douglas G
authors.initials: DG
authors.lastname: Altman
authors.forename: Stuart A
authors.initials: SA
authors.lastname: Taylor
authors.forename: David
authors.initials: D
authors.lastname: Manning
authors.forename: Steve
authors.initials: S
authors.lastname: Halligan
mesh_terms: D000328:Adult; D015415:Biomarkers; D002983:Clinical Competence / Q000706:statistics & numerical data; D003111:Colonic Polyps / Q000000981:diagnostic imaging*; D023881:Colonography, Computed Tomographic / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D015588:Observer Variation; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results
chemical_list: D015415:Biomarkers