Gastroenterologie
a hepatologie

The role of CT colonography in large bowel investigation

Hana Straková¹, Ludvík Straka ^{Orcid.org  2}

+ Affiliation
¹ Radiodiagnostické oddělení, Uherskohradišťská nemocnice a. s., Uherské Hradiště
² Gastroenterologická ambulance, Uherskohradišťská nemocnice a. s., Uherské Hradiště

Summary

CT colonography (CTC, virtual colonoscopy) is a non-invasive colonic imaging method that uses computed tomography (CT) with advanced graphic software to create two-and three-dimensional images of the colon. CTC is indicated mainly for the diagnosis of colorectal neoplasia in cases where conventional colonoscopy is incomplete or contraindicated, as well as in cases where the patient finds conventional colonoscopy intolerable or refuses conventional colonoscopy. Compared to a barium enema, CTC has higher sensitivity for the detection of colorectal neoplasia and has similar or lower levels of radiation exposure. Sensitivity for the detection of polyps ≥ 6 mm is similar to that of conventional colonoscopy. Intravenous injection of iodine contrast media is usually not required; therefore, CTC is safe in patients with iodine allergy or chronic renal failure. Both adequate bowel cleansing and distension are essential to ensure optimal examinations, which are then assessed by radiologists and reported using the standardized C-RADS classification system (CT colonography reporting and data system). CTC does not cover all conventional colonoscopy indications; for instance, CTC is not recommended for the diagnosis of colon inflammatory conditions (including inflammatory bowel disease) or familial polyposis syndromes, and it has low diagnostic value for anal pathologies. CTC is not the official primary method for colorectal cancer screening in the Czech Republic. The aim of this paper is to discuss CTC specifics and indications.

Keywords

CT colonography, colorectal cancer, colonoscopy, polyps, screening, virtual colonoscopy

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