Original InvestigationFlat (Nonpolypoid) Colorectal Lesions Identified at CT Colonography in a U.S. Screening Population
Section snippets
Materials and Methods
The data source for this study was derived from screening CTC at a single institution in 5107 consecutive asymptomatic adults (2783 women, 2324 men; mean age, 56.9 ± 7.2 years) over a 51-month period from April 2004 through June 2008. This study cohort consisted of generally healthy outpatient adults representing a typical US screening population. The specific protocol used for bowel preparation, colonic distention, multidetector CT scanning, and interpretation of CTC has been previously
Prevalence and Histologic Features of Polyps Detected on CTC
A total of 954 nondiminutive colorectal lesions were identified in 636 individuals, of which 125 lesions (13.1%) in 106 adults were prospectively categorized as flat and 829 were labeled as polypoid (sessile or pedunculated) or masslike. The mean size (ie, the maximum lesion diameter excluding any stalk) of nondiminutive flat lesions was 12.7 mm (rang, 6–80 mm; Figure 1, Figure 2, Figure 3). According to polyp size categories, 73 flat lesions were small (6–9 mm) and 52 were large (≥10 mm). Of
Discussion
Since the original description of flat adenomas by Muto et al (17) in 1985, the true prevalence and clinical significance of nonpolypoid colorectal lesions has been widely debated. In particular, the relevance of flat lesions for colorectal cancer screening in the United States has not been well established. Our findings confirm that even when more stringent morphologic criteria are applied, flat lesions (ie, superficially elevated) do exist in a typical US screening population. Although they
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Cited by (49)
The Natural History of Colorectal Polyps: Overview of Predictive Static and Dynamic Features
2018, Gastroenterology Clinics of North AmericaComputed Tomography Colonography vs Colonoscopy for Colorectal Cancer Surveillance After Surgery
2018, GastroenterologyCitation Excerpt :The performance characteristics we report for CTC in the surveillance setting are somewhat lower than those in the screening setting, although the results are more comparable for polyps ≥10 mm. The inability of CTC to identify flat polyps is a potential concern in both screening and surveillance settings.23,24 Our study, in contrast to some recent reports,16 did not identify a significant difference in detection rates for serrated vs non-serrated polyps.
Imaging and Screening for Colorectal Cancer with CT Colonography
2017, Radiologic Clinics of North AmericaCitation Excerpt :The dual contrast tagging regimen likely improves the accuracy of CTC in several ways: (1) it increases specificity by tagging residual stool (barium effect) and decreases the amount of adherent stool (iohexol effect), (2) it increases sensitivity by allowing for detection in polyps submerged under fluid (iohexol effect), and (3) it improves detection of serrated and other flat lesions via surface coating of adherent contrast.26–29 This focal contrast coating can serve as a vital beacon for detection for flat lesions that may otherwise be relatively inconspicuous against the adjacent bowel mucosa (Fig. 1) and is also seen frequently in tubulovillous adenomas and other advanced neoplasms (Fig. 2).30–32 Once considered optional, these advantages demonstrate why the use of oral contrast tagging is now considered standard practice for CTC.
Current Issues in Computed Tomography Colonography
2016, Seminars in Ultrasound, CT and MRIScreening for Colorectal Cancer: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force
2021, JAMA - Journal of the American Medical Association