Nonadenomatous polyps at CT colonography: prevalence, size distribution, and detection rates

To prospectively investigate with computed tomographic (CT) colonography the prevalence and size distribution of nonadenomatous polyps in asymptomatic adults and to compare the detection rates of adenomatous and nonadenomatous polyps.

A total of 1233 asymptomatic adults (mean age, 57.8 years; 505 women, 728 men) underwent same-day CT colonography and optical colonoscopy procedures. CT colonoscopy studies were interpreted prospectively with a primary three-dimensional approach immediately before optical colonoscopy. Statistical analysis was performed with the chi(2) test. Size, prevalence, and by-polyp detection differences were compared between adenomatous and nonadenomatous polyps.

Seven hundred fifty-six (57.7%) colorectal polyps identified at optical colonoscopy in 410 (33.3%) patients were nonadenomatous; of these lesions, 622 (82.3%) were diminutive (

More than 80% of nonadenomatous polyps were diminutive, but they accounted for nearly 40% of polyps that were 6 mm or larger. Fortunately, CT colonography is significantly (P <.01) less sensitive in the detection of lesions that have no malignant potential when compared with similar-sized adenomas that have malignant potential.