Findings on optical colonoscopy after positive CT colonography exam.
OBJECTIVE
The aim of this study is to evaluate the findings on optical colonoscopy (OC) after a positive CT colonography (CTC) exam and characterize the type of polyps seen on OC but not reported by CTC.


METHODS
Over an 18-month period a total of 159 asymptomatic adults had polyps seen on computed tomography colonography examination and subsequently underwent planned therapeutic optical colonoscopy. The colonoscopists were aware of the findings on CT colonography prior to further evaluation of the colon. Characteristics of polyps and adenomas seen on subsequent optical colonoscopy but not seen or reported on CT colonography were examined.


RESULTS
The adenoma miss rate for CT colonography overall was 18.9% (25/132) including 6.2% (4/65) for polyps >9 mm and 18.2% (8/44) for polyps 6-9 mm. Three of the adenomas >9 mm not seen on CTC were sessile, and two were found in patients with technically difficult CT colonography studies due to poor colonic distention. No adenomas with advanced pathology <6 mm were found on optical colonoscopy but not reported on CT colonography. False-positive CTC referral where no polyp was seen on colonoscopy was 5.0%.


CONCLUSIONS
CT colonography has adenoma miss rates similar to miss rates historically found with optical colonoscopy, with most missed adenomas being <10 mm and sessile in shape.
Section of Gastroenterology and Hepatology, Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin 53792-5124, USA.
Daniel
D
Cornett
Courtney
C
Barancin
Brent
B
Roeder
Mark
M
Reichelderfer
Terrance
T
Frick
Deepak
D
Gopal
David
D
Kim
Perry J
PJ
Pickhardt
Andrew
A
Taylor
Patrick
P
Pfau
D000236:Adenoma / Q000175:diagnosis* / Q000601:surgery; D000368:Aged; D000369:Aged, 80 and over; D002276:Carcinoid Tumor / Q000175:diagnosis* / Q000601:surgery; D015331:Cohort Studies; D003110:Colonic Neoplasms / Q000175:diagnosis* / Q000601:surgery; D003111:Colonic Polyps / Q000175:diagnosis* / Q000601:surgery; D023881:Colonography, Computed Tomographic; D003113:Colonoscopy; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests