title: Comparison of the relative sensitivity of CT colonography and double-contrast barium enema for screen detection of colorectal polyps.
abstract: OBJECTIVE
  In a population reflective of a screening setting, our aim was to compare the relative sensitivity and specificity of computed tomography (CT) colonography with double-contrast barium enema (DCBE) for detection of colorectal polyps and to assess the added value of double reading at CT colonography, using endoscopy as the arbiter.
  
  
  METHODS
  This prospective, blinded study comprised 837 asymptomatic persons at higher than average risk for colorectal cancer who underwent CT colonography followed by same-day DCBE. Examinations with polyps > or =5 mm in diameter were referred to colonoscopy.
  
  
  RESULTS
  CT colonography readers detected 56%-79% of polyps > or =10 mm in diameter. In comparison, the sensitivity at DCBE varied between 39% and 56% for the 31 polyps > or =1 cm. All of the readers detected more polyps at CT colonography than DCBE, but the difference was statistically significant for only a single reader (P = 0.02). Relative specificity for polyps > or =10 mm on a per-patient basis ranged from 96% to 99% at CT colonography, and 99%-100% at DCBE. Doubly read CT colonography detected significantly more polyps than DCBE (81% vs. 45% for polyps > or =1 cm [P = <0.01], and 72% vs. 44% for polyps 5-9 mm [P < or = 0.01]).
  
  
  CONCLUSIONS
  Double-read CT colonography is significantly more sensitive in detecting polyps than single-read double contrast barium enema. DCBE was significantly more specific than CT colonography.
authors.affiliation: Department of Radiology, Mayo Clinic Rochester, MN 55905, USA.
authors.forename: C Daniel
authors.initials: CD
authors.lastname: Johnson
authors.forename: Robert L
authors.initials: RL
authors.lastname: MacCarty
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Welch
authors.forename: Lynn A
authors.initials: LA
authors.lastname: Wilson
authors.forename: William S
authors.initials: WS
authors.lastname: Harmsen
authors.forename: Duane M
authors.initials: DM
authors.lastname: Ilstrup
authors.forename: David A
authors.initials: DA
authors.lastname: Ahlquist
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001466:Barium Sulfate; D003111:Colonic Polyps / Q000000981:diagnostic imaging* / Q000473:pathology; D023881:Colonography, Computed Tomographic / Q000379:methods*; D003113:Colonoscopy / Q000379:methods; D015179:Colorectal Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D004733:Enema; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011336:Probability; D011446:Prospective Studies; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D016037:Single-Blind Method; D007507:Therapeutic Irrigation / Q000379:methods
chemical_list: D001466:Barium Sulfate