Feasibility study of computed tomography colonography using limited bowel preparation at normal and low-dose levels study.
The purpose was to evaluate low-dose CT colonography without cathartic cleansing in terms of image quality, polyp visualization and patient acceptance. Sixty-one patients scheduled for colonoscopy started a low-fiber diet, lactulose and amidotrizoic-acid for fecal tagging 2 days prior to the CT scan (standard dose, 5.8-8.2 mSv). The original raw data of 51 patients were modified and reconstructed at simulated 2.3 and 0.7 mSv levels. Two observers evaluated the standard dose scan regarding image quality and polyps. A third evaluated the presence of polyps at all three mSv levels in a blinded prospective way. All observers were blinded to the reference standard: colonoscopy. At three times patients were given questionnaires relating to their experiences and preference. Image quality was sufficient in all patients, but significantly lower in the cecum, sigmoid and rectum. The two observers correctly identified respectively 10/15 (67%) and 9/15 (60%) polyps > or =10 mm, with 5 and 8 false-positive lesions (standard dose scan). Dose reduction down to 0.7 mSv was not associated with significant changes in diagnostic value (polyps > or =10 mm). Eighty percent of patients preferred CT colonography and 13% preferred colonoscopy (P<0.001). CT colonography without cleansing is preferred to colonoscopy and shows sufficient image quality and moderate sensitivity, without impaired diagnostic value at dose-levels as low as 0.7 mSv.
Florie
Jasper
J
Department of Radiology, Academic Medical Center, G1-230, P.O. Box 22660, 1100 DD, Amsterdam, The Netherlands. J.Florie@amc.uva.nl
van Gelder
Rogier E
RE
Schutter
Michiel P
MP
van Randen
Adrienne
A
Venema
Henk W
HW
de Jager
Steven
S
van der Hulst
Victor P M
VP
Prent
Anna
A
Bipat
Shandra
S
Bossuyt
Patrick M M
PM
Baak
Lubbertus C
LC
Stoker
Jaap
J
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002400:Cathartics / Q000008:administration & dosage; D016009:Chi-Square Distribution; D023881:Colonography, Computed Tomographic / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007417:Intestinal Polyps / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D010342:Patient Acceptance of Health Care; D011446:Prospective Studies; D011829:Radiation Dosage; D012044:Regression Analysis; D018709:Statistics, Nonparametric; D011795:Surveys and Questionnaires
D002400:Cathartics