Stool tagging applied in thin-slice multidetector computed tomography colonography.
OBJECTIVE
To compare thin-slice multidetector computed tomography colonography (CTC) that uses stool tagging with colonoscopy.


METHODS
One hundred fifty patients scheduled for colonoscopy underwent high-resolution CTC. An iodinated contrast agent was added to the preparation to tag the residual colonic fluid and stool. The effect of fluid tagging was assessed first. Sensitivity and specificity were calculated for two independent readers. In addition, values were recalculated separately for the first and last 75 patients.


RESULTS
Tagging was optimal in 95.3% of the cases, and reader confidence was high. Sensitivities were 64.1%-66.7% (for the 2 readers) for 5- to 9-mm polyps and 91.7% for larger polyps. The overall specificity was 94.2% and 95%. Sensitivity improved during the study for both 5- to 9-mm polyps (from 54.2%-58.3% to 80%) and polyps larger than 9 mm (from 50% to 100%). Specificity changed nonuniformly.


CONCLUSIONS
The combination of fluid tagging and high-resolution scanning in CTC showed high sensitivity and specificity, especially concerning sensitivity for polyps of 10 mm and larger.
Thomeer
Maarten
M
Department of Radiology, University Hospitals, Catholic University of Leuven, Leuven, Belgium. maartenthomeer@yahoo.com
Carbone
Iacopo
I
Bosmans
Hilde
H
Kiss
Gabriel
G
Bielen
Didier
D
Vanbeckevoort
Dirk
D
Van Cutsem
Eric
E
Rutgeerts
Paul
P
Marchal
Guy
G
D003106:Colon / Q000000981:diagnostic imaging*; D003111:Colonic Polyps / Q000175:diagnosis* / Q000453:epidemiology; D023881:Colonography, Computed Tomographic; D003113:Colonoscopy / Q000379:methods; D015179:Colorectal Neoplasms / Q000175:diagnosis / Q000453:epidemiology; D005189:False Positive Reactions; D005243:Feces / Q000737:chemistry*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008067:Lipoma / Q000175:diagnosis / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012680:Sensitivity and Specificity