title: The efficacy of intravenous contrast-enhanced 16-raw multidetector CT colonography for detecting patients with colorectal polyps in an asymptomatic population in Korea.
abstract: OBJECTIVE
  The purpose of this study is to compare the sensitivity of computed tomography (CT) colonography (CTC) with that of colonoscopy for detecting patients with colorectal polyps in an asymptomatic screening population in Korea, thus to evaluate a possibility, whether CTC could be used as a screening tool for colorectal polyps.
  
  
  METHODS
  A total of 241 asymptomatic adults underwent intravenous contrast-enhanced CTC and colonoscopy successively on the same day. Bowel preparation was performed by 4 L of polyethylene glycol (n=172) or 90 mL of sodium phosphate (n=69). The CTC findings were released to the colonoscopists after the first examination of each segment, a procedure known as segmental unblinded colonoscopy, and were used as the reference standard. The diagnostic performance of CTC for colorectal polyps was calculated.
  
  
  RESULTS
  The per-patient sensitivities of CTC were 68.5% (37/54) and 86.7% (13/15) for polyp > or = 6 and > or = 10 mm, inferior to those of colonoscopy, 92.6% (50/54) and 100% (15/15), respectively. The per-polyp sensitivities of CTC were 60.4% (61/101) and 72.7% (16/22) for polyp > or = 6 and > or = 10 mm, respectively. The low sensitivity of CTC was related with flat morphology. CTC detected only 37.5% (9/24) of flat polyps > or = 6 mm. Bowel preparation by sodium phosphate further decreased the positive predictive value and specificity than by polyethylene glycol.
  
  
  CONCLUSIONS
  Screening by CTC with asymptomatic population was not promising in Korea despite using advanced CT technology (16-row detector). Bowel preparation was one of the key determinants of the specificity of CTC.
authors.affiliation: Seoul National University Hospital, Healthcare System Gangnam Center, Healthcare Research Institute, Seoul, Korea.
authors.forename: Young Sun
authors.initials: YS
authors.lastname: Kim
authors.forename: Nayoung
authors.initials: N
authors.lastname: Kim
authors.forename: Se Hyung
authors.initials: SH
authors.lastname: Kim
authors.forename: Min Jung
authors.initials: MJ
authors.lastname: Park
authors.forename: Seon Hee
authors.initials: SH
authors.lastname: Lim
authors.forename: Jeong Yoon
authors.initials: JY
authors.lastname: Yim
authors.forename: Kyung Ran
authors.initials: KR
authors.lastname: Cho
authors.forename: Sun Sin
authors.initials: SS
authors.lastname: Kim
authors.forename: Dong Hee
authors.initials: DH
authors.lastname: Kim
authors.forename: Hyo Won
authors.initials: HW
authors.lastname: Eun
authors.forename: Kyoung Soo
authors.initials: KS
authors.lastname: Cho
authors.forename: Jeong Hoon
authors.initials: JH
authors.lastname: Kim
authors.forename: Byung Inhn
authors.initials: BI
authors.lastname: Choi
authors.forename: Hyun Chae
authors.initials: HC
authors.lastname: Jung
authors.forename: In Sung
authors.initials: IS
authors.lastname: Song
authors.forename: Chan Soo
authors.initials: CS
authors.lastname: Shin
authors.forename: Sang-Heon
authors.initials: SH
authors.lastname: Cho
authors.forename: Byung-Hee
authors.initials: BH
authors.lastname: Oh
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging / Q000503:physiopathology; D018253:Adenoma, Villous / Q000000981:diagnostic imaging / Q000503:physiopathology; D003110:Colonic Neoplasms / Q000000981:diagnostic imaging / Q000503:physiopathology; D003111:Colonic Polyps / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D023881:Colonography, Computed Tomographic / Q000379:methods*; D003113:Colonoscopy / Q000379:methods; D003287:Contrast Media; D005260:Female; D006801:Humans; D007723:Korea; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media