Diagnosing colorectal polyps and masses - the use of CT colonography

Colorectal cancer is common, over 13,000 cases were diagnosed in Australia in 2005. The pathogenesis of colorectal cancer has been well investigated and usually occurs in a predictable sequence progressing from dysplasia, to carcinoma in situ before becoming an invasive malignancy. The symptoms and signs of colorectal polyps and masses are often nonspecific, however, given that polyps are easily cured with polypectomy, it is vital to have an accurate and acceptable diagnostic test. Traditional tests include conventional (optical) colonoscopy and double contrast barium enema. Computed tomographic (CT) colonography is a newer, minimally invasive method for examining the colon for colorectal polyps.

To inform general practitioners about CT colonography, its evidence, indications, controversies and extracolonic ancillary findings.

The evidence supporting CT colonography is discussed along with how it is performed, as well as a discussion of the factors unique to it, such as extracolonic findings and polyp management.