The efficacy of intravenous contrast-enhanced 16-raw multidetector CT colonography for detecting patients with colorectal polyps in an asymptomatic population in Korea.
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.
Kim
Young Sun
YS
Seoul National University Hospital, Healthcare System Gangnam Center, Healthcare Research Institute, Seoul, Korea.
Kim
Nayoung
N
Kim
Se Hyung
SH
Park
Min Jung
MJ
Lim
Seon Hee
SH
Yim
Jeong Yoon
JY
Cho
Kyung Ran
KR
Kim
Sun Sin
SS
Kim
Dong Hee
DH
Eun
Hyo Won
HW
Cho
Kyoung Soo
KS
Kim
Jeong Hoon
JH
Choi
Byung Inhn
BI
Jung
Hyun Chae
HC
Song
In Sung
IS
Shin
Chan Soo
CS
Cho
Sang-Heon
SH
Oh
Byung-Hee
BH
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
D003287:Contrast Media