title: CT colonography: effect of computer-aided detection of colonic polyps as a second and concurrent reader for general radiologists with moderate experience in CT colonography.
abstract: OBJECTIVE
  To assess the effectiveness of computer-aided detection (CAD) as a second reader or concurrent reader in helping radiologists who are moderately experienced in computed tomographic colonography (CTC) to detect colorectal polyps.
  
  
  METHODS
  Seventy CTC datasets (34 patients: 66 polyps ≥6 mm; 36 patients: no abnormalities) were retrospectively reviewed by seven radiologists with moderate CTC experience. After primary unassisted evaluation, a CAD second read and, after a time interval of ≥4 weeks, a CAD concurrent read were performed. Areas under the receiver operating characteristic (ROC) curve (AUC), along with per-segment, per-polyp and per-patient sensitivities, and also reading times, were calculated for each reader with and without CAD.
  
  
  RESULTS
  Of seven readers, 86% and 71% achieved a higher accuracy (segment-level AUC) when using CAD as second and concurrent reader respectively. Average segment-level AUCs with second and concurrent CAD (0.853 and 0.864) were significantly greater (p < 0.0001) than average AUC in the unaided evaluation (0.781). Per-segment, per-polyp, and per-patient sensitivities for polyps ≥6 mm were significantly higher in both CAD reading paradigms compared with unaided evaluation. Second-read CAD reduced readers' average segment and patient specificity by 0.007 and 0.036 (p = 0.005 and 0.011), respectively.
  
  
  CONCLUSIONS
  CAD significantly improves the sensitivities of radiologists moderately experienced in CTC for polyp detection, both as second reader and concurrent reader.
  
  
  CONCLUSIONS
  • CAD helps radiologists with moderate CTC experience to detect polyps ≥6 mm. • Second and concurrent read CAD increase the radiologist's sensitivity for detecting polyps ≥6 mm. • Second read CAD slightly decreases specificity compared with an unassisted read. • Concurrent read CAD is significantly more time-efficient than second read CAD.
authors.affiliation: Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Waehringer Guertel 18-20, 1090, Vienna, Austria, thomas.mang@meduniwien.ac.at.
authors.forename: Thomas
authors.initials: T
authors.lastname: Mang
authors.forename: Luca
authors.initials: L
authors.lastname: Bogoni
authors.forename: Vikram X
authors.initials: VX
authors.lastname: Anand
authors.forename: Dass
authors.initials: D
authors.lastname: Chandra
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Curtin
authors.forename: Anna S
authors.initials: AS
authors.lastname: Lev-Toaff
authors.forename: Gerardo
authors.initials: G
authors.lastname: Hermosillo
authors.forename: Ralph
authors.initials: R
authors.lastname: Noah
authors.forename: Vikas
authors.initials: V
authors.lastname: Raykar
authors.forename: Marcos
authors.initials: M
authors.lastname: Salganicoff
authors.forename: Robert
authors.initials: R
authors.lastname: Shaw
authors.forename: Susan
authors.initials: S
authors.lastname: Summerton
authors.forename: Rafel F R
authors.initials: RF
authors.lastname: Tappouni
authors.forename: Helmut
authors.initials: H
authors.lastname: Ringel
authors.forename: Michael
authors.initials: M
authors.lastname: Weber
authors.forename: Matthias
authors.initials: M
authors.lastname: Wolf
authors.forename: Nancy A
authors.initials: NA
authors.lastname: Obuchowski
mesh_terms: D000368:Aged; D000465:Algorithms; D002983:Clinical Competence; D003111:Colonic Polyps / Q000000981:diagnostic imaging*; D023881:Colonography, Computed Tomographic / Q000379:methods*; D003936:Diagnosis, Computer-Assisted; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D011871:Radiology; D015203:Reproducibility of Results; D012189:Retrospective Studies; D000078329:Workforce